The Compact Clause and the National Popular Vote Interstate Compact: Revisiting One Critic’s Arguments as the Compact Gains Momentum – N.Y.U. Journal of Legislation & Public Policy

By Hannah Langsam

November 4, 2025

While the requirements to enact a constitutional amendment have doomed past attempts at Electoral College reform, the National Popular Vote Interstate Compact (NPVIC) proposes an alternate pathway: because states have the power to choose how to apportion their electors, if enough states agree to submit their electoral votes in accordance with the nationwide popular vote, then the nationally chosen candidate would be the guaranteed victor at the Electoral College. This proposal would nominally retain the Electoral College, but de facto replace it with a national popular vote.

Among the criticisms of the NPVIC are claims that it is an interstate compact that would violate the Compact Clause. While the Supreme Court has rarely discussed the Compact Clause’s congressional consent requirement, it seems clear that only those compacts that threaten federal supremacy are subject to its conditions. This paper revisits and responds to a prominent critique of the NPVIC by Professor Derek T. Muller and argues that, because it does not enlarge state power at the expense of the national government, the NPVIC would not need congressional consent to be effective.

I. The National Popular Vote Interstate Compact (NPVIC)

As the Supreme Court will readily admit, “the Electoral College was designed by men who did not want the election of the President to be left to the people.”¹ The Electoral College is, by its design, unconcerned with which candidate the people select. And, indeed, the people do not directly elect the president; the states do. While the Electoral College and the national popular vote are generally aligned, this result is not guaranteed. The Electoral College has selected five national popular vote losers, including George W. Bush in 2000 and Donald Trump in 2016. With “the specter of a[nother] ‘wrong winner’ loom[ing],” calls to reform or abolish the Electoral College have mounted in recent years.²

Opposition to the Electoral College is hardly a new phenomenon. Since 1804, legislators have introduced more than 700 proposals to amend or eliminate the Electoral College.³ These attempts, however, have failed to satisfy the onerous conditions required to amend the Constitution. Under Article V, a constitutional amendment must pass both the House and the Senate by a two-thirds majority (or, if proposed in a constitutional convention, by the approval of two-thirds of state legislatures) and be subsequently ratified by three-fourths of the states (38 out of 50).⁴ Only seventeen proposals since the Bill of Rights have successfully cleared Article V’s high thresholds.⁵ As a result, the Electoral College remains intact, despite 221 years of sustained calls for reform.

Enter the National Popular Vote Interstate Compact (NPVIC).⁶ The NPVIC, or the “Agreement Among the States to Elect the President by National Popular Vote,” presents a potential pathway for reforming (or effectively abolishing) the Electoral College that avoids the “cumbersome and glacially slow” constitutional amendment process.⁷ Under this agreement, compacting states and the District of Columbia would jointly disregard their populations’ chosen candidate and agree to apportion all of their electoral votes to whomever wins the overall nationwide popular vote.⁸

The NPVIC sidesteps Article V’s requirements by routing reform through a piecemeal, state-by-state approach rooted in states’ electoral authority. Signatories join the compact by enacting National Popular Vote laws in their respective legislatures to change the process by which they appoint presidential electors, which is a power that the Constitution clearly vests in the states.⁹ To avoid a potential collective action problem, the legislation is both contingent and binding: the NPVIC is only effective once the number of electoral votes promised by participating states exceeds the threshold required to win the Electoral College (currently, at least 270 out of 538 total votes), and signatories cannot withdraw from the agreement after July 20 of an election year.¹⁰ These two provisions ensure that, once a critical mass of states have signed on, the nationwide popular vote will determine the winner of the presidential election. If successful, the NPVIC would establish a de facto direct election while nominally retaining the structure of the Electoral College, obviating the need to amend the Constitution.

As of the end of 2024, seventeen states and D.C. had enacted NPVIC legislation, totaling 209 electoral votes.¹¹ In the nineteen years since its initial proposal, the NPVIC has continued to gain momentum. Seven states joined in the last six years, including Minnesota in 2023 and Maine in 2024.¹² Additionally, as of October 28, 2025, versions of the National Popular Vote bill are pending in three state legislatures.¹³ Given this continued interest, it seems plausible that the NPVIC may soon reach its requisite 270 electoral vote activation threshold.

The NPVIC relies primarily on states’ authority to choose how their presidential electoral votes are apportioned, vested by Article II, § 1 of the Constitution.¹⁴ Enumerated grants of power, however, are not necessarily unfettered and may be subject to other constitutional limitations. No one disputes states’ right to unilaterally allocate their electoral votes according to the nationwide popular vote regardless of their own population’s selected candidate,¹⁵ and rightfully so: this clearly falls within each state’s exclusive purview, as the Supreme Court has affirmed.¹⁶ Signatories of the NPVIC, however, are not acting independently. Instead, each has passed coordinated legislation contingent on other states agreeing to adopt the same measures and will be collectively bound only once that threshold is met.

It is this coordination that may subject the NPVIC to limitations from either the Compact Clause (Article I, § 10, cl. 3) or the Treaty Clause (Article I, § 10, cl. 1). While states are proscribed from entering into “treat[ies],” they may, with congressional approval, form “agreement[s] or “compact[s].”¹⁷ Although some scholars have argued that the NPVIC may fall within the Treaty Clause’s ambit, and thus be wholly invalid irrespective of congressional authorization,¹⁸ this essay assumes that the NPVIC is not a treaty, but may instead be an “agreement” or “compact.”¹⁹ If the NPVIC is indeed a “compact,” as its name suggests, would it be subject to the Compact Clause’s consent strictures? Answering this question requires wading through the Compact Clause’s sparse and murky jurisprudence to determine which agreements it regulates.

II. The Compact Clause

A. The History of the Compact Clause

The meaning of the Compact Clause is a mystery. It declares: “No State shall, without the Consent of Congress, . . . enter into any Agreement or Compact with another State.”²⁰ The Supreme Court has only interpreted the Compact Clause a handful of times, and the relevant archival records are “barren of any clue as to the precise contours of the agreements and compacts [it] governed.”²¹ However scant the Compact Clause’s history may be, its origins provide some guidance for understanding its current landscape.

Interstate agreements and compacts existed before the Constitution. While the Articles of Confederation precluded states from entering into “treat[ies], confederation[s], or alliance[s]” without congressional consent, it placed no restrictions on states’ ability to form agreements or compacts.²² During that time, much of the squabbling among the states arose from controversies over interstate compacts that lacked congressional authorization.²³ The Constitution, responding to the Articles of Confederation’s infirmities, imposed new prohibitions on interstate action via the Treaty Clause and the Compact Clause: “an absolute prohibition on treaties, alliances, and federations, and a qualified prohibition on agreements and compacts,” permissible only with congressional approval.²⁴ Beyond comparing the treatment of interstate compacts in the Constitution to the Articles of Confederation, there is little evidence that could offer insight into the purpose and meaning of the Compact Clause. The Compact Clause only appears once in the Federalist Papers, when James Madison declared its justifications “either so obvious, or . . . so fully developed, that [it] may be passed over without remark.”²⁵ Apparently, the virtues of congressional consent, presumably as a bulwark against the interstate disputes that fomented disunity and eroded the national government under the Articles of Confederation, were so plain and inoffensive that the Compact Clause was not worth debating. Indeed, it passed the Convention with ease.²⁶ While this history offers some insight into the Framers’ intent as to the function of the Compact Clause, the precise meanings they ascribed to the terms “treaty,” “agreement,” and “compact” “were soon lost”²⁷ and “remain[] elusive.”²⁸

B. **The Virginia v. Tennessee Test for Congressional Consent**

Given this dearth of historical evidence, the Supreme Court’s interpretation of the Compact Clause is the primary authority for ascertaining its meaning. On the rare occasions that the Court has spoken on the Compact Clause, it has consistently reaffirmed a reading that is contrary to the plain meaning of the text. The Compact Clause, the Court tells us, “[can] not be read literally.”²⁹ The terms “agreement” and “compact” are so broad that, if taken literally, would give Congress sweeping authority over “all forms of stipulation, written or verbal, and relating to all kinds of subjects.”³⁰ Inferring that the Framers did not intend for the Compact Clause’s strictures to apply to “every possible compact or agreement between one state and another,”³¹ the Court instead concluded that “agreement” and “compact” are “terms of art” ascribed with denotations different from their colloquial meanings.³² Under the Court’s narrow reading, congressional consent is required for only some, and not all, interstate agreements and compacts.

Scholars agree that the case law unequivocally places some interstate compacts outside of the Compact Clause.³³ Despite this consensus, there is considerable disagreement over the proper test for determining whether an interstate “agreement” or “compact” falls within the Compact Clause’s ambit. The Supreme Court first articulated its non-literal interpretation of the Compact Clause in dictum in Virginia v. Tennessee (1893),³⁴ which it later reaffirmed as a holding in New Hampshire v. Maine (1976).³⁵ The Court continues to follow Virginia v. Tennessee to divide interstate agreements into two categories: those that require congressional consent and those that do not. In that case, the Court determined that the Compact Clause regulates only those agreements that may “increase . . . the political power or influence of the States affected, and thus encroach . . . upon the full and free exercise of Federal authority.”³⁶ By contrast, compacts with which the federal government “can have no possible objection or have an interest in interfering”—such as interstate land sales, shipping arrangements, and coordinated responses to emergent threats like epidemic—are excepted from the Compact Clause’s strictures.³⁷

Narrowing the Compact Clause’s operation to stipulations “tending to the increase of political power in the states [that] may encroach upon or interfere with the just supremacy of the United States” comports with what can be inferred from the legislative history.³⁸ The Framers drafted the Compact Clause under the specter of the impotent Articles of Confederation, and unbridled interstate compacts were a source of strife that undermined the viability of the early national government.³⁹ Given this context, it makes sense to understand the Compact Clause as concerned primarily with agreements that impact federal sovereignty. As the Court indicated in Virginia v. Tennessee, the Compact Clause’s restrictions are designed to preserve vertical federalism, or the balance of power between the national government and the states.⁴⁰

Importantly, a compact’s impact on state power is not independently sufficient to subject it to the Compact Clause’s purview. Rather, the enlargement or contraction of state political power is relevant to the Compact Clause analysis only to the extent that these effects impede on federal power.⁴¹ Put differently, state power is only germane insofar as it “displace[s] the relation . . . of the states to the general government.”⁴² Interstate compacts that impact state political power, but in no way threaten states’ subordination to the national government or “interfere with [its] rightful management of particular subjects placed under [its] entire control,” do not implicate the Compact Clause’s concerns and therefore do not require congressional authorization.⁴³ Virginia v. Tennessee repeatedly clarifies this distinction: every mention of state power is cabined within the central concern of federal supremacy.⁴⁴

The Supreme Court revisited this test in U.S. Steel Corp. v. Multistate Tax Commission (1978) (hereinafter “U.S. Steel”). At issue was the Multistate Tax Compact, an agreement to promote multistate uniformity and compatibility among members’ tax systems, including by creating a Multistate Tax Commission with auditing and some enforcement authority over consenting states.⁴⁵ The agreement did not go into effect until a requisite number of states joined.⁴⁶Upholding the challenged compact as constitutionally valid despite the absence of congressional consent, the Court declined to return to a plain reading of the Compact Clause.⁴⁷ Instead, the Court reiterated its fidelity to the narrow interpretation articulated in Virginia v. Tennessee, which it had explicitly embraced only two terms prior in New Hampshire v. Maine.⁴⁸ The Compact Clause, the Court said, is designed to preserve “the proper balance between federal and state power,” or vertical federalism.⁴⁹ Interstate stipulations that do not implicate that purpose are not subject to its congressional consent requirement.

To determine whether a compact requires congressional consent, courts must consider “whether the Compact enhances state power quoad the National Government.”⁵⁰ Applying this test, the Court decided that several characteristics of the Multistate Tax Agreement exempted it from the consent requirement: it did not “purport to authorize . . . powers [member states] could not exercise” independently; it did not “delegat[e] . . . sovereign power” to the commission it created; and members could withdraw from the agreement “at any time.”⁵¹ Even though “[g]roup action [under the compact] may be more influential than independent actions,” the Court concluded that any enhancement in state power would not be at the expense of the national government and therefore did not concern the Compact Clause.⁵²

Justice White, joined by Justice Blackmun, dissented. Because Justice White’s dissent features prominently in some scholars’ analyses and application of Compact Clause doctrine, it is important to attend to. Justice White disagreed with the majority’s conclusion on three fronts. First, he asserted that the majority did not ascribe sufficient weight to the relevant “federal interests” that could be implicated by the Multistate Tax Compact: to Justice White, the federal interests in this case raised a “potential” threat to federal supremacy due to the prospect of future conflict between the Compact and legislation that Congress might choose to pass in this area.⁵³ The problem with this argument, however, is that a compact that implicates a federal interest does not necessarily interfere with Congress’s ability to legislate in the same space and so does not undermine “federal supremacy.”⁵⁴ Further, the presence of a federal interest alone is not sufficient to subject an interstate agreement to the Compact Clause’s consent requirements. If it were, “virtually all interstate agreements . . . would require congressional approval,” which is the exact outcome the Court’s non-literal reading of the Compact Clause sought to avoid.⁵⁵ Instead, the Compact Clause is more narrowly concerned with impermissible interference with national authority. Not all federal interests implicate federal sovereignty, and absent this threat, “the existence of a federal interest is irrelevant.”⁵⁶

Second, Justice White took issue with the challenged compact’s “conditional pre-commitment scheme.”⁵⁷ The Multistate Tax Compact did not become effective in any of the ratifying states until a threshold quantity of states joined. According to Justice White, the assurance this design guarantees distinguishes it from other compacts.⁵⁸He criticized the majority’s dismissal of these concerns as lacking.⁵⁹ If its only purpose were to require consent for interstate agreements that would otherwise violate existing constitutional provisions, “[the Compact Clause] would have no independent meaning.”⁶⁰ Because it cannot be the case that the Compact Clause is surplusage, there must be some actions that states can permissibly take unilaterally that are impermissible in concert.⁶¹ Although Justice White’s reasoning here feels logically sound, he misunderstands how the majority delineates between valid and invalid interstate compacts. Under the majority’s test, coordinated interstate conduct absent congressional authorization is only impermissible insofar as it threatens national authority. The nature of collective action transforms otherwise constitutionally permissible conduct to a threat to federal supremacy. Rather than render the Compact Clause surplusage, the majority’s test identified a distinct class of prohibited conduct.

Third, Justice White argued that the majority failed to account for the challenged compact’s impact on non-compacting states, which he asserted is an independent concern sufficient to trigger the Compact Clause’s requirements. Despite insisting that “[t]here is no want of authority for [this] conclusion,” Justice White cited only two Supreme Court cases (both of which preceded Virginia v. Tennessee), one district court case, and academic scholarship to support his proposition.⁶² The majority did, however, contemplate the effects of the challenged compact on nonmembers.⁶³ But unlike in Justice White’s dissent, the Court did not weigh this consideration in a vacuum. Rather, whether a compact “benefit[s]” some states “to the harm of others” was only material to the majority’s analysis to the extent the effects threatened to displace federal sovereignty.⁶⁴ Both the majority’s explicit text and the internal reasoning of its arguments emphasize that no independent state interest, divorced from the question of the “just supremacy of the United States,” exists.⁶⁵Non-compacting states are not independently pertinent to the Compact Clause inquiry, and any resulting reshuffling of state power is not alone sufficient to trigger the congressional consent requirement.

Thus, U.S. Steel reiterated the test set forth in Virginia v. Tennessee: the Compact Clause requires congressional approval only for stipulations that “encroach upon or impair the supremacy” of the national government.⁶⁶ This interpretation of the Compact Clause continues to control today.⁶⁷ Critically, this inquiry is “functional,” as opposed to categorical.⁶⁸ Rather than proscribe a particular class of agreements, the Court’s case-by-case analyses of interstate compacts interrogate whether they impermissibly impede on federal supremacy.⁶⁹ Because the vast majority of interstate agreements do not interfere with federal authority, the non-literal reading of the Compact Clause exempts all but a narrow category of “agreement[s] or compact[s]” from the consent requirement.⁷⁰ As of October 2025, the Supreme Court has never invalidated any interstate agreement for want of congressional consent.⁷¹

C. Professor Derek T. Muller’s Alternative Reading of the Compact Clause

In his 2007 article for the Election Law Journal, Professor Derek T. Muller offered an alternative articulation of the Compact Clause inquiry.⁷² While Professor Muller is far from the NPVIC’s only critic, his article is worth revisiting because his scholarship continues to be widely cited in debates over the NPVIC, both inside and outside of legal scholarship.⁷³ According to Professor Muller, the Compact Clause “allows states freely to enter into non-political compacts, but requires political compacts—those that interfere with either federal or non-compacting state sovereignty interests—to receive congressional approval.”⁷⁴ Given how sparse the Compact Clause’s doctrinal landscape is and how unpredictable case-by-case tests can be, Professor Muller’s impulse to identify an intelligible rule that neatly categorizes all interstate stipulations is understandable. Unfortunately, the rule he identifies does not accurately reflect the case law. While the Supreme Court has not spoken on the Compact Clause often, on the few occasions that it has, its jurisprudence is consistent and clear: “the test is whether the Compact enhances state power quoad the National Government.”⁷⁵

Professor Muller divided interstate compacts into two categories: “political,” which require congressional consent, and “non-political,” which do not.⁷⁶ While certainly some of the Supreme Court’s Compact Clause cases are concerned with political power, the phrase “political compact” does not appear in any of them.⁷⁷ Instead, the Supreme Court has emphasized that the Compact Clause’s concerns are fact-based.⁷⁸ While Professor Muller’s initial approach may seem categorical, he subsequently⁷⁹ refined the distinction between “political” and “non-political” compacts to reflect the Virginia v. Tennessee/U.S. Steel instruction to consider how compacts “function.”⁸⁰

However, where he locates this inquiry diverges from the Court’s articulation of the Compact Clause. According to Professor Muller, in the absence of congressional approval, encroaching on “either” the authority of the national government “or” the political power of non-compacting states is sufficient to render an interstate compact invalid.⁸¹ Professor Muller essentially replaces the Supreme Court’s chosen preposition, “quoad,” with “or.” From this disjunctive, he derives a “sister state interest test” that is separate and distinct from the federal supremacy inquiry.⁸² Under this interpretation, the Compact Clause is dually concerned with preserving both vertical federalism, or the balance of power between the federal government and the states, and horizontal federalism, or the balance of power among individual states. Professor Muller points to the Supreme Court’s cases, namely U.S. Steel, to support his analysis.⁸³ However, there exists no independent concern for “non-compacting state sovereignty interests” that could implicate the Compact Clause. While it may be true that “[e]very Compact Clause case, from Virginia v. Tennessee to the modern cases, considers . . . the interests of non-compacting sister states,”⁸⁴ the operative question is why the Court assesses those interests. An impact on non-compacting state interests could demonstrate that the compact has enhanced state power, but the Compact Clause, under the Supreme Court’s reading, is not concerned with state power qua state power. Rather, its concern is with interstate compacts that enhance state power so as to interfere with federal sovereignty.⁸⁵ Any impact on state power that does not impair the national government’s supremacy is not relevant.⁸⁶

Professor Muller finds support for a standalone state interest in U.S. Steel.⁸⁷ In his view, the majority rejected the petitioner’s sister state concerns not as nonexistent, but rather as insufficiently implicated to trigger the Compact Clause.⁸⁸ To Professor Muller, this implies that “the sister state interest may render a compact unconstitutional.”⁸⁹ However, the Court considered and rejected this argument.⁹⁰ States are “free to adopt” policies that negatively impact other states.⁹¹ This action would only be of constitutional interest if it offends nonmembers’ “sovereignty” to such an extent that “transgresses the bounds of the [Constitution]” and “our federal structure is implicated.”⁹² Even assuming that Professor Muller’s articulated “state interest” is equivalent to “state sovereignty,”⁹³ an impact on state sovereignty alone—without a corresponding connection to federal supremacy—is not sufficient to subject the challenged compact to the Compact Clause. The Court explained that “an affront to” state sovereignty would only be relevant if the compact’s collective action imposed such “pressure” as to violate other constitutional provisions, thereby threatening national supremacy.⁹⁴ The Court did not “appl[y] the sister state interest test” to find that the asserted state interest was not sufficiently strong, as Muller argues.⁹⁵ Instead, the Court’s reasoning rejected the existence of that independent interest altogether.

Professor Muller also relies heavily on Justice White’s dissent in U.S. Steel as support for the “sister state interest test.”⁹⁶ If Justice White’s opinion were adopted by the majority, it would provide substantial support for this claim.⁹⁷ However, as Professor Muller later acknowledged, Justice White’s statement is “just a dissent.”⁹⁸ To this criticism, he reiterates that the majority “acknowledged the validity of the interest of non-compacting states,”⁹⁹ which, as discussed, is an incomplete articulation of the Court’s repeated refrain of “state power quoad the National Government.”¹⁰⁰ Further, the very fact that Justice White did not think that the majority sufficiently attended to sister state interests suggests that this consideration was not part of the majority’s reasoning.

Professor Muller posits that the Court’s lack of attention to horizontal federalism is historical “happenstance”; that is, it is simply the product of the facts of the Court’s Compact Clause cases.¹⁰¹ If the Court faced an agreement that more readily implicated “sister state interests,” he argues, that concern would feature more prominently. But the Court’s analyses have not been so confined. In Virginia v. Tennessee, the Court’s interpretation of the Compact Clause’s purpose and scope was wholly divorced from the facts of the case; the Court went beyond the specific considerations before it to expound in dicta on the proper application of the Compact Clause.¹⁰² If horizontal federalism were such a significant concern to be independently sufficient to bring a compact within the Compact Clause’s ambit, there is no reason why the Court would not have announced that here. Further, Justice White’s dissent invited the U.S. Steel Court to weigh “sister state interests” as a distinct consideration, and it declined to do so.¹⁰³ The more logical inference to be drawn from this conspicuous absence is that horizontal federalism is not a relevant concern.

The Compact Clause is not independently concerned with the interests of non-compacting sister states. While state power often is relevant, any consideration cannot be disentangled from the Compact Clause’s primary purpose: the preservation of vertical federalism.¹⁰⁴ Because the Compact Clause’s jurisprudence is largely a judicial creation born from scant historical evidence, it is possible that the Court may, in the future, announce “sister state interests” as an additional and discrete inquiry that may provide a sufficient basis to trigger the consent requirements. But that is not the test today. The Compact Clause only requires congressional consent for agreements that impermissibly enhance state power to the detriment of federal sovereignty.

III. Does the NPVIC Require Congressional Consent?

Applying the “state power quoad the National Government” test reveals that the NPVIC does not require congressional consent. Although it is an “interstate compact,” it does not expand state power at the expense of federal supremacy. Rather, the NPVIC concerns an area exclusive to the states with which the national government “can have no possible … interest in interfering.”¹⁰⁵

A. Is the NPVIC a “Compact” Under the Compact Clause?

The National Popular Vote Interstate Compact is, unsurprisingly, a “compact.” Of course, the NPVIC’s title is not dispositive.¹⁰⁶ Calling what is arguably a series of unilateral contingent National Popular Vote laws a “compact” may be an unnecessary concession.¹⁰⁷ However, the Supreme Court has interpreted the terms “agreement” and “compact” quite broadly to embrace “the formation of any combination” of states.¹⁰⁸ Further, there is no meaningful difference between informal “agreement[s]” and “more formalized ‘compact[s]’”¹⁰⁹; even “mutual declarations” have the potential to implicate the Compact Clause.¹¹⁰ The NPVIC is almost certainly an “agreement” or “compact” and is therefore not per se exempt from the Compact Clause’s requirements.

B. Does the NPVIC Impermissibly Encroach on Federal Sovereignty?

Interstate agreements or compacts “must be judged in terms of enhancement of state power in relation to the Federal Government.”¹¹¹ Because the NPVIC is an interstate “compact,” it would require congressional consent to become effective if it “enhances state power quoad the National Government.”¹¹² This functional inquiry creates a two-step test:¹¹³ first, does the NPVIC increase compacting states’ power? If so, does this enlarged power interfere with federal authority? The following analysis reveals that, while the NPVIC aims to shuffle the comparative political effectiveness of states’ electoral votes, such shifts do not amount to an infringement on non-compacting states’ power. Even if the NPVIC would enhance the power of members at the expense of nonmembers, the resulting increases would occur in an arena delegated exclusively to the states and thus does not offend federal supremacy. As such, the NPVIC is likely exempt from the Compact Clause’s congressional authorization requirement.

1. Does the NPVIC Enhance Member States’ Power?

Signatories of the NPVIC agree to cast their electoral votes for the winner of the nationwide popular vote, notwithstanding their own statewide results. This commitment is only triggered when enough states have joined to guarantee that the winner of the Electoral College is also the winner of the popular vote.

According to Professor Muller, this guarantee robs non-compacting states of political power to the benefit of compacting states because the winner of the Electoral College would be determined solely by the electoral votes submitted by NPVIC signatories.¹¹⁴ While nonmembers would remain free to apportion their electors according to their chosen methods, their electoral votes would have no effect on the outcome of the presidential election.¹¹⁵ Of course, states could unilaterally decide to appoint presidential electors based on the winner of the nationwide election. The problem with the NPVIC, Professor Muller argues, is its collective nature, which is contingent on a guaranteed outcome.¹¹⁶ By its design, the NPVIC disempowers states that do not join by guaranteeing that the outcome of the presidential election is determined by those states that agree to apportion electoral votes in their jointly desired manner: according to the national popular vote.

In this respect, Professor Muller and proponents of the NPVIC are in agreement: the purpose of the compact is to ensure that the electoral votes of member states are what determine the selection of the president. Less clear, however, is what constitutionally relevant interest this shift would implicate.

Even if U.S. Steel could be interpreted to embrace a concern for sister state interests, “coordinated state action designed to achieve otherwise unattainable goals” would be permissible so long as it does not threaten the sovereignty of nonmember states.¹¹⁷ While the NPVIC may render non-compacting states’ electoral votes irrelevant, this does not readily impede on their sovereignty. The Presidential Electors Clause vests states with the exclusive authority to determine how to appoint their electors.¹¹⁸ The right to implement an apportionment scheme that enhances the political value of a state’s votes is inherent in this “plenary” power.¹¹⁹

For instance, most states allocate their presidential electors according to a winner-take-all system: all of their electoral votes go to the candidate chosen in the statewide election.¹²⁰ This was not always the case. The popularity of this scheme surged more than forty years after the ratification of the Constitution, when several state legislatures adopted it.¹²¹ There are no constitutional or federal limitations that would prevent these states from enacting new statutes to implement different apportionment schemes.¹²²

Still, the winner-take-all system is widespread. Although the Framers organized electoral clout based on population and size, the winner-take-all system redistributes this weight according to partisan makeup, increasing the political value of swing states and diminishing the relevance of Republican or Democratic strongholds.¹²³ The fact that the widely-used winner-take-all system enhances the value of some states at the expense of others contrary to the inherent design of the Electoral College is not sufficient to render it unconstitutional.¹²⁴ From the Constitution’s tolerance for the winner-take-all system, it is clear that states change their comparative political utility without infringing on other states’ sovereignty. Like the winner-take-all system, the NPVIC may reshuffle the current balance of electoral influence. However, this exercise of states’ Presidential Electors Clause rights would not amount to an infringement on non-compacting states’ sovereignty.

Professor Muller disagrees: “The evisceration of political effectiveness is a sufficient interest to invoke the constitutional safeguard of congressional consent.”¹²⁵ He argues that the power to appoint electors implies the right to meaningfully contribute to the selection of the President.¹²⁶ This reading of the Presidential Electors Clause cannot be squared with how the Electoral College functions. In every election, states cast electoral votes that end up politically meaningless, either because they selected the losing candidate or because the winning candidate already surpassed the 270-vote threshold.¹²⁷ If the Constitution guaranteed them not only the right to cast votes, but the right to cast influential votes, then many states’ sovereignty would be violated every four years. Critical for Professor Muller, however, is states’ loss of political influence “ex ante.”¹²⁸ This predetermined deprivation, he says, sets the NPVIC apart from other procedures or outcomes that affect comparative political utility.¹²⁹ The constitutional relevance of this “ex post”/“ex ante” distinction is unclear. While non-compacting states’ electoral votes would, ex ante, bear no influence on the outcome of the presidential election under the NPVIC, the fact of meaningless votes is inherent in the structure of the Electoral College.

Most importantly, it is not clear whether political effectiveness is the same thing as constitutionally relevant political power. Under both the current winner-take-all system and the NPVIC, states’ power to choose the manner in which their electors are appointed, as granted by the Constitution, remains solidly intact. Indeed, that right is the premise on which the NPVIC is based. In either model, some states’ electors will count toward the selected president’s votes, and some states’ will not. While the NPVIC would guarantee which states cast the “winning” votes, this reshuffling would not impact any state’s Presidential Electors Clause powers. The NPVIC, therefore, would not enhance members’ power at the expense of nonmembers.

2. Does the Enhancement of State Power Encroach on Federal Sovereignty?

Even if the NPVIC’s reshuffling of political effectiveness did amount to a constitutionally relevant comparative shift in state power, this impact alone would not be sufficient to implicate the Compact Clause’s consent requirement. Any increase in political power at the expense of non-compacting states is only relevant insofar as it bears on federal sovereignty.

As Virginia v. Tennessee and U.S. Steel instruct, compacts that impermissibly enlarge states’ power to encroach on federal supremacy are invalid.¹³⁰ This includes proclaiming to authorize states to do something that was constitutionally committed to the federal government and is therefore outside the bounds of their otherwise plenary power.¹³¹ The NPVIC does not. Instead, NPVIC signatories exercise a power explicitly enumerated to them in the Constitution: determining the method by which they award electoral votes.¹³² As the foregoing discussion makes clear, states are free to assign presidential electors in the manner of their choosing, including the winner-take-all system, the congressional district method, or by the national popular vote. Because the Constitution entitles states to choose to allocate electoral votes based on the nationwide, as opposed to their statewide, election, the NPVIC does not “purport to authorize . . . any powers [states] could not exercise in its absence.”¹³³

Further, the NPVIC does not “interfere with [the federal government’s] rightful management of particular subjects placed under [its] entire control” because the Constitution vests the power to appoint presidential electors exclusively in the states.¹³⁴ As the Supreme Court confirmed in McPherson v. Blacker (1892), “the appointment and mode of appointment of electors belong exclusively to the states.”¹³⁵ Because the power signatories exercise is exclusive to the states, there exists no federal supremacy on which the NPVIC could intrude.

Compare the NPVIC to the Multistate Tax Compact. The latter implicated tax and interstate commerce, both of which are areas in which the Constitution permits federal action.¹³⁶ Yet, the Court concluded that it did not threaten or impair Congress’s powers in these areas, and so it did not require congressional consent.¹³⁷ Unlike tax or commerce, the NPVIC concerns conduct that is the exclusive province of the states. If the Multistate Tax Compact did not interfere with the national government’s constitutionally granted powers, it cannot be the case that the NPVIC, which operates in an area where no federal intervention is even permitted, would. Even Professor Muller agrees: “it is doubtful” that the NPVIC would interfere with federal sovereignty.¹³⁸

Because the Constitution exclusively empowers the states to determine how they allocate presidential electors, no federal authority exists for the NPVIC to threaten. Even if the NPVIC would increase members’ power at the expense of nonmembers, it would not encroach on national sovereignty. Since the NPVIC would not “enhance state power quoad the Federal Government,” it is exempt from the Compact Clause’s congressional consent requirement.

IV. Conclusion

The NPVIC offers a potential avenue to reform the Electoral College while circumventing the onerous constitutional amendment process. Critics argue that the NPVIC is an interstate compact that, under the Compact Clause, would require congressional authorization. However, the Compact Clause only demands congressional consent for those compacts that threaten federal supremacy. Because the NPVIC is rooted in signatories’ exercise of powers exclusively delegated to the states, it would not increase state power to the detriment of the national government. The NPVIC is therefore outside the scope of the Compact Clause’s concerns and is exempt from its consent strictures. While the NPVIC may face other obstacles in becoming effective, the Compact Clause would not be one of them.

Hannah Langsam, J.D. Class of 2026, N.Y.U. School of Law.

Suggested Citation: Hannah Langsam, The Compact Clause and the National Popular Vote Interstate Compact: Revisiting One Critic’s Arguments as the Compact Gains Momentum, N.Y.U. J. Legis. & Pub. Pol’y Quorum (2025).

Notes

1
Gray v. Sanders, 372 U.S. 368, 376 n.8 (1963).
2
Adam Schleifer, Interstate Agreement for Electoral Reform, 40 Akron L. Rev. 717, 720–21 (2007).
3
Thomas H. Neale & Andrew L. Nolan, Cong. Rsch. Serv., R43823, The National Popular Vote (NPV) Initiative: Direct Election of the President by Interstate Compact 1 (2019); see also Schleifer, supra note 2, at 720. The true figure is potentially much higher. Derek Muller’s article, which was written over a decade prior to the CRS report, locates over a thousand failed attempts. Derek T. Muller, The Compact Clause and the National Popular Vote Interstate Compact, 6 Election L. J. 372, 374 (2007) [hereinafter The Compact Clause].
4
U.S. Const. art. V.
5
U.S. Const. amends. I-X; XI-XXVII.
6
John R. Koza et al., Every Vote Equal: A State-Based Plan for Electing the President by National Popular Vote 255–58 (National Popular Vote Press 4th ed. 2013).
7
Schleifer, supra note 2, at 718.
8
Koza et al., supra note 6.
9
U.S. Const. II, § 1.
10
Koza et al., supra note 6, at 275, 723.
11
California (54 electoral votes), Colorado (10 electoral votes), Connecticut (7 electoral votes), Delaware (3 electoral votes), D.C. (3 electoral votes), Hawaii (4 electoral votes), Illinois (19 electoral votes), Maine (4 electoral votes), Maryland (10 electoral votes), Massachusetts (11 electoral votes), Minnesota (10 electoral votes), New Jersey (14 electoral votes), New Mexico (5 electoral votes), New York (28 electoral votes), Oregon (8 electoral votes), Rhode Island (4 electoral votes), Vermont (3 electoral votes), and Washington (12 electoral votes) have all enacted the National Popular Vote bill. State Status, National Popular Vote, https://www.nationalpopularvote.com/state-status (last visited Apr. 2025) [https://perma.cc/TB8N-8VJY]; Neale & Nolan, supra note 3, at 9.
12
News History, National Popular Vote, https://www.nationalpopularvote.com/news-history (last visited Apr. 2025) [https://perma.cc/G3UZ-26YS].
13
Kansas (H.B. 2257), Pennsylvania (H.B. 270), and South Carolina (H. 3870). Election Administration Legislation Tracker, Ballotpedia, https://legislation.ballotpedia.org/elections/search?category=National%20Popular%20Vote%20Interstate%20Compact&session=2025&page=1 (last visited Oct. 28 2025) [https://perma.cc/M5T6-MWMU].
14
U.S. Const. art. II, § 1.
15
See, e.g., Muller, The Compact Clause, supra note 3, at 393.
16
McPherson v. Blacker, 146 U.S. 1, 35 (1892) (unanimous opinion) (“[T]he appointment and mode of appointment of electors belong exclusively to the [s]tates under the Constitution of the United States.”).
17
U.S. Const. art. I, § 10.
18
Jennifer S. Hendricks, Popular Election of the President: Using or Abusing the Electoral College?, 7 Election L. J. 218, 220–224 (2008) (arguing that an alternative, “strong-arm” form of the NPVIC would be a treaty).
19
The NPVIC contains many characteristics common to interstate compacts. Like the Multistate Tax Compact at issue in U.S. Steel, the NPVIC is not effective until a specified threshold of states adopt it, and it contains procedures for withdrawal and termination. Koza et al., supra note 6, at 259–60. Many of the NPVIC’s fiercest advocates emphasize its contract-like quality as its primary benefit: by imbuing signatories with “bind[ing],” “contractual obligations,” the NPVIC guarantees that all of its members will comply with the agreed-upon electoral vote apportionment procedure, regardless of which candidate wins in each individual state. Id. at 207. It would be hard to argue that a binding interstate contract is somehow not also “the formation of [a] combination of states.” Virginia v. Tennessee, 148 U.S. at 519. The NPVIC is almost certainly an “agreement” or “compact” and is therefore not per se exempt from the Compact Clause’s requirements. It is worth noting that whether the NPVIC would be enforceable remains an open question. If a member state violates agreed-upon procedures and decides to apportion its electoral votes to a candidate other than the winner of the nationwide popular vote, what would be the recourse? It seems plausible that the courts would decline to weigh in, citing the political question doctrine. Although the issue of enforcement is outside the scope of this essay, this is an important area for further inquiry before implementing the NPVIC.
20
U.S. Const. art. I, § 10, cl. 3.
21
U.S. Steel Corp. v. Multistate Tax Comm’n, 434 U.S. 452, 460–61 (1978).
22
See Articles of Confederation art. VI.
23
Michael S. Greve, Compacts, Cartels, and Congressional Consent, 68 Mo. L. Rev. 285, 297 (2003).
24
Schleifer, supra note 2, at 729.
25
Id. (quoting The Federalist No. 44, 281 (James Madison) (Clinton Rossiter ed., 1961)).
26
Muller, The Compact Clause, supra note 3, at 379.
27
U.S. Steel, 434 U.S. at 463. See also Muller, The Compact Clause, supra note 3, at 379.
28
Muller, The Compact Clause, supra note 3, at 379.
29
U.S. Steel, 434 U.S. at 459.
30
Virginia v. Tennessee, 148 U.S. 503, 518 (1893).
31
Id. As the above analysis suggests, divinations about the Framers’ intentions for the Compact Clause are on somewhat dubious historical footing.
32
U.S. Steel, 434 U.S. at 462.
33
U.S. Steel, 434 U.S. at 489 (White, J., dissenting). See, e.g., Ian J. Drake, Federal Roadblocks: The Constitution and the National Popular Vote Interstate Compact, 44 Publius: The Journal of Federalism 681, 686 (2013); Greve, supra note 23, at 288; Hendricks, supra note 18, at 220; Muller, The Compact Clause, supra note 3, at 383; Schleifer, supra note 2, at 733, 738.
34
Virginia v. Tennessee, 148 U.S. at 518–521.
35
Schleifer, supra note 2, at 732. See also New Hampshire v. Maine, 426 U.S. 363, 369–70 (1976).
36
Virginia v. Tennessee, 148 U.S. at 520.
37
Id. at 518.
38
Id. at 519.
39
James Madison, Preface to the Debates in the Convention, in Notes of Debate in the Federal Convention of 1787, at 14 (Adrienne Koch ed., Ohio University Press 1984) (“Federal authority was violated . . . by [interstate] compacts without the consent of Congress[.]”).
40
Virginia v. Tennessee, 148 U.S. at 518–19 (stating that only agreements that “tend to increase and build up the political influence of the contracting states” in a way that “encroach[es] upon or impair[s]” federal sovereignty would be constitutionally invalid absent congressional consent).
41
See, e.g., Hendricks, supra note 18, at 224–26.
42
Virginia v. Tennessee, 148 U.S. at 521.
43
Id. at 518.
44
See, e.g., id. at 520 (stating that the inquiry is whether the compact “may lead or not to the increase of the political power or influence of the States affected, and thus encroach or not upon the full and free exercise of Federal authority.”).
45
U.S. Steel, 434 U.S. at 457, 475.
46
Id. at 454.
47
Id. at 460 (“[W]e are reluctant to . . . circumscribe modes of interstate cooperation that do not enhance state power to the detriment of federal supremacy.”).
48
New Hampshire v. Maine, 426 U.S. at 369–70.
49
U.S. Steel, 434 U.S. at 471.
50
Id. at 473. See also id. at 471 (“The relevant inquiry must be one of the impact on our federal structure”), 472 (“[The compact] must be judged in terms of enhancement of state power in relation to the federal government.”).
51
Id. at 473. Hans von Spakovsky has argued that these indicia are prongs of a three-factor test, and the absence of any of the described characteristics is sufficient to subject an interstate compact to the congressional consent requirement. Hans von Spakovsky, Destroying the Electoral College: The Anti-Federalist National Popular Vote Scheme, Heritage Found. (Oct. 27, 2011), https://www.heritage.org/election-integrity/report/destroying-the-electoral-college-the-anti-federalist-national-popular [https://perma.cc/ETB3-QRNT]. This is a misreading of the majority’s opinion. These characteristics do not determine whether a compact requires congressional consent to become effective. The only required consideration that the Court has consistently weighed is whether the stipulation impermissibly enhances state power at the expense of the national government. While these characteristics may guide a court in analyzing an interstate compact, they should not be conflated with necessary conditions of Compact Clause-compatible agreements. A compact may possess all, some, or even none of these characteristics and still be exempted from the Compact Clause’s strictures. See U.S. Steel, 434 U.S. at 472–73 (listing these characteristics as evidence that “[o]n its face [the challenge compact] contains no provisions that would enhance the political power of the member States in a way that encroaches upon the supremacy of the United States”). See also Koza et al., supra note 6, at 642–44.
52
U.S. Steel, 434 U.S. at 473.
53
Id. at 484, 490 (White, J., dissenting).
54
Id. at 479–80 n.33 (“Federal power in the relevant areas remains plenary; no action authorized by the Constitution is ‘foreclosed.’”).
55
Id.
56
Id.
57
Schleifer, supra note 2, at 733.
58
U.S. Steel, 434 U.S. at 493 (White, J., dissenting).
59
Id. at 482, 490–91 (White, J., dissenting) (“[T]he majority has but one repeated answer: that each member State is free to adopt the procedures in question just as it could as if the Compact did not exist[.]”).
60
Id. at 482 (White, J., dissenting).
61
Id.
62
Id. at 494 n.23 (White, J., dissenting).
63
Id. at 477-78.
64
Id. This distinction is discussed in greater detail below.
65
Id. at 479 n.33 (quoting Virginia v. Tennessee, 148 U.S. at 519).
66
Virginia v. Tennessee, 148 U.S. at 518.
67
Muller, The Compact Clause, supra note 3, at 383 (interpreting the test differently, but stating that the Virginia v. Tennessee test “still controls today.”).
68
U.S. Steel, 434 U.S. at 468; see also Hendricks, supra note 18, at 225.
69
U.S. Steel, 434 U.S. at 468–73. See, e.g., New Hampshire v. Maine, 426 U.S. at 369-70; Northeast Bancorp, Inc. v. Bd. of Governors of the Fed. Rsrv. Sys., 472 U.S. 159, 176 (1985) (“We do not see how the statutes in question . . . enhance the political power of the New England states at the expense of other States or have an ‘impact on our federal structure.’”) (emphasis in original).
70
U.S. Const. art. I, § 10, cl. 3.
71
Muller, The Compact Clause, supra note 3, at 390; Schleifer, supra note 2, at 734.
72
Muller, The Compact Clause, supra note 3.
73
See, e.g., Thomas Jipping, The National Popular Vote: Misusing an Interstate Compact to Bypass the Constitution, Heritage Found. 4 n.34, 9 n.64 (Oct. 8, 2020), https://www.heritage.org/civil-rights/report/the-national-popular-vote-misusing-interstate-compact-bypass-the-constitution [https://perma.cc/Z76Q-V3PL] (citing Muller in support of the argument that the NPVIC requires congressional consent); Neale & Nolan, supra note 3, at 26 n.158–59 (discussing Muller’s arguments that the NPVIC requires congressional consent due to horizontal federalism concerns); Wikipedia, Constitutionality of the National Popular Vote Interstate Compact, https://en.wikipedia.org/wiki/Constitutionality_of_the_National_Popular_Vote_Interstate_Compact [https://perma.cc/MGL2-UH8P] (last visited Sept. 28, 2025) (citing Muller as one “legal commentator[] [who] ha[s] argued that the power of non-compacting states would be altered” by the NPVIC); Derek T. Muller, The Electoral College and the Federal Popular Vote, 15 Harv. L. & Pol’y Rev. 129, 143 n.73 (2020) (citing his prior articles challenging the constitutionality of the NPVIC in an article that advances other arguments against the NPVIC beyond constitutional critiques).
74
Muller, The Compact Clause, supra note 3, at 377.
75
U.S. Steel, 434 U.S. at 473.
76
Professor Muller’s original article does not directly define “political” and “non-political.” See Hendricks, supra note 18, at 225. Professor Jennifer S. Hendricks argues that Muller’s categorical approach obscures and “simplif[ies]” the Court’s actual test by relocating the focus from the compact’s effect to its topic. Hendricks, supra note 18, at 225. If a compact involves “political” matters, like elections, then it would automatically require congressional consent, regardless of whether it in fact encroaches on federal supremacy. Id. In response to this criticism, Muller clarified that, while not all compacts implicating political issues necessarily require congressional consent, the NPVIC would because of its effect on “political power,” defined as “the capacity to influence the activities of the body politic.” Muller, More Thoughts on the Compact Clause and the National Popular Vote: A Response to Professor Hendricks, 7 Election L. J. 227, 230 (2008) [hereinafter More Thoughts] (quoting Black’s Law Dictionary 1197 (8th ed. 2004)).
77
See, e.g., Virginia v. Tennessee, 148 U.S. 503; U.S. Steel, 434 U.S. 452; Northeast Bancorp, 472 U.S. 159. Muller located his “political”/“non-political” framing in the Court’s attention to “political power” in its Compact Clause analyses. Muller, More Thoughts, supra note 76, at 229.
78
See, e.g., Virginia v. Tennessee, 148 U.S. at 520-21 (weighing the particular features of the challenged compact); U.S. Steel, 434 U.S. at 472–76 (same); Northeast Bancorp, 472 U.S. at 175–76 (same).
79
Muller, More Thoughts, supra note 76, at 230.
80
U.S. Steel, 434 U.S. at 468. See also Greve, supra note 23 at 368–76 (discussing the “functional” test for congressional consent); Hendricks, supra note 18, at 225 (noting U.S. Steel’s “functional” test); Schleifer, supra note 2, at 733 (“[T]he Court . . . confirmed the functional test set out [in Virginia v. Tennessee.]”).
81
Muller, The Compact Clause, supra note 3, at 377, 390.
82
Id. at 392.
83
Id. at 385-86.
84
Id. at 385.
85
See Drake, supra note 33, at 689 (“[T]he Compact Clause’s standard is whether federal supremacy is threatened by an ‘encroachment or interference through enhanced state power[.]’”) (quoting U.S. Steel, 434 U.S. at 480 n. 33); Greve, supra note 23 at 285 (acknowledging that U.S. Steel holds that “[the Compact] Clause applies only to state compacts that ‘encroach’ upon federal supremacy” but arguing that the case was “wrongly decided”); Hendricks, supra note 18, at 224–25 (articulating the Virginia v. Tennessee/U.S. Steel test as “whether [a compact] increases state power at the expense of national supremacy”).
86
See Virginia v. Tennessee, 148 U.S. at 518–21.
87
See Muller, The Compact Clause, supra note 3, at 385–86. Muller points to Northeast Bancorp v. Board of Governors as another example of this phenomenon. According to Muller, although the Northeast Bancorp Court rejected the state interest concern as insufficient to bring the challenged stipulation within the ambit of the Compact Clause, the fact that it weighed that consideration at all is proof of its existence. Id. at 387. This evidence is unpersuasive. In Northeast Bancorp, the Court declined to determine whether the interstate action at issue amounted to a “compact” or “agreement” within the Compact Clause. Instead, in response to petitioner’s allegation that the challenged conduct “impermissibly offends the sovereignty of sister States,” the Court declared dismissively and simply that, “We do not see how the statutes in question either enhance the political power of the New England States at the expense of other States or have an ‘impact on our federal structure,’” quoting U.S. Steel. Northeast Bancorp, 472 U.S. at 176.
88
Muller, The Compact Clause, supra note 3, at 386.
89
Just not the Multistate Tax Compact. Id. at 387.
90
U.S. Steel, 434 U.S. at 477–78 (“[E]ven if” the compact did “redound to the benefit of any particular group of [s]tates or to the harm of others,” that alone would not be sufficient to implicate the Compact Clause.)
91
Id. at 477.
92
Id. at 478.
93
The two are almost certainly not equivalent, given the Court’s careful distinction between “federal interest” and “federal supremacy.” U.S. Steel, 434 U.S. at 479 n.33.
94
See id. at 478. The Court pointed to the Commerce Clause and the Privileges and Immunities Clause, as the Multistate Tax Compact implicated these federal powers. Id.
95
Muller, The Compact Clause, supra note 3, at 392. Notably, there is disagreement among scholars on this point. Professor Hendricks seems sympathetic to Professor Muller’s emphasis on non-compacting states, whereas Schleifer seems more aligned with my understanding. Hendricks, supra note 18, at 225 (“[T]he majority of the Court was willing to tolerate coordinated state action to achieve otherwise unattainable goals, so long as the sovereign rights of other states remained intact.”); Schleifer, supra note 2, at 731 (“The Court here seems to ask whether the power of the states is altered, but only as a proxy for how the states are affected in their relationship to the federal government.”).
96
Id. at 386 (“[T]he sister state interest of the Compact Clause [is] most lucidly stated in Justice White’s dissent[.]”). See also id. at 389.
97
U.S. Steel, 434 U.S. at 494 (White, J., dissenting) (expressing dismay over the majority’s inattentiveness to state interests).
98
Muller, More Thoughts, supra note 76, at 228. Ian Drake points to Cuyler v. Adams (1981), in which the Court cited White’s dissent “with approval,” to buttress the persuasive authority he and Muller ascribe to it. Drake, supra note 33, at 690. However, the Cuyler Court invoked White’s language about factors that Congress, not the courts, takes into account when making the “political judgment” of whether to approve a compact, which is inapplicable to Muller’s “sister state” interest test. See 449 U.S. 433, 440 n.8 (1981).
99
Muller, More Thoughts, supra note 76, at 228.
100
U.S. Steel, 434 U.S. at 473.
101
Hendricks, supra note 18, at 225 (discussing Muller, The Compact Clause, supra note 3, at 385–87). Professor Michael Greve, whom Muller cites, raises a similar argument. Greve, supra note 23, at 301. See also Schleifer, supra note 2, at 731, 740–41.
102
Virginia v. Tennessee, 148 U.S. at 517–21, 525 (announcing the Court’s modern interpretation of the Commerce Clause despite holding that Congress had impliedly consented to the challenged compact at issue, rendering it unnecessary for the Court to determine when congressional consent is required).
103
U.S. Steel, 434 U.S. at 479 n.33 (addressing the dissent’s concerns about federal interests at length but apparently ignoring the dissent’s concerns about state interests).
104
Schleifer, supra note 2, at 733 (“[T]he Court . . . indicated unmistakably that it is vertical, and not horizontal issues of state power that are relevant to the inquiry regarding consent[.]”).
105
Virginia v. Tennessee, 148 U.S. at 518.
106
Muller, The Compact Clause, supra note 3, at 388.
107
Neale & Nolan, supra note 3, at 23.
108
Virginia v. Tennessee, 148 U.S. at 519.
109
U.S. Steel, 434 U.S. at 470–71; Virginia v. Tennessee, 148 U.S. at 520.
110
Virginia v. Tennessee, 148 U.S. at 520.
111
U.S. Steel, 434 U.S. at 472.
112
Id. at 473.
113
See Drake, supra note 33, at 686.
114
Muller, The Compact Clause, supra note 3, at 391–92.
115
Muller, The Compact Clause, supra note 3, at 391; see also Drake, supra note 33, at 687.
116
Muller, The Compact Clause, supra note 3, at 393.
117
Hendricks, supra note 18, at 225.
118
U.S. Const. art. II, § 1, cl. 2.
119
McPherson, 146 U.S. at 24, 35 (upholding scheme determining the state’s chosen candidate according to the winner from each congressional district, as opposed to a state-wide popular vote). Because the Electoral College is zero sum, enhancing the worth of one state diminishes the worth of the others.
120
48 states and D.C. employ the winner-take-all method. Hendricks, supra note 18, at 219.
121
Koza et al., supra note 6, at 637–38.
122
Both Maine and Nebraska have different systems. Hendricks, supra note 18, at 219.
123
Katherine Florey, Losing Bargain: Why Winner-Take-All Vote Assignment is the Electoral College’s Least Defensible Feature, 68 Case W. Rsrv. L. Rev. 317, 345–60 (2017).
124
See Williams v. Va. State Bd. of Elections, 288 F. Supp. 622, 628–29 (E.D. Va. 1968), aff’d, 393 U.S. 320 (1969) (per curiam).
125
Muller, The Compact Clause, supra note 3, at 391.
126
Muller, More Thoughts, supra note 76, at 231–32 (“It is not a bare power to appoint electors qua electors sine potente; it is a power to appoint electors whose role is to elect the President.”).
127
See Hendricks, supra note 18, at 226.
128
Muller, More Thoughts, supra note 76, at 231.
129
Id.
130
U.S. Steel, 434 U.S. at 472; Virginia v. Tennessee, 148 U.S. at 519.
131
U.S. Steel, 434 U.S. at 473 (upholding the challenged compact because, among other reasons, “[it] does not purport to authorize the member States to exercise any powers they could not exercise in its absence”); U.S. Const. amend. X.
132
U.S. Const. art. II, § 1, cl. 2.
133
U.S. Steel, 434 U.S. at 473.
134
Virginia v. Tennessee, 148 U.S. at 518; U.S. Const. art. II, § 1, cl. 2.
135
McPherson, 146 U.S. at 35.
136
U.S. Const. art. I, § 8, cl. 1, 3.
137
U.S. Steel, 434 U.S. at 472–73.
138
Muller, The Compact Clause, supra note 3, at 390. Some scholars have argued that the NPVIC implicates “federal interests” sufficient to bring it within the ambit of the Compact Clause, including protecting the constitutional amendment process, the stability and preservation of the Electoral College, and the power vested in the House of Representatives to select the president if the Electoral College fails. Tara Ross, Federalism & Separation of Powers: Legal and Logistical Ramifications of the National Popular Vote Plan, 11 The Federalist Soc’y 40 (2010); Drake, supra note 33, at 684; Schleifer, supra note 2, at 739–40. While these interests may exist, mere existence of a “federal interest” is not equivalent to an interference with “federal sovereignty,” as U.S. Steel makes clear. U.S. Steel, 434 U.S. at 479 n.33. Because only infringements on national sovereignty implicate the Compact Clause, these identified interests are likely not sufficiently significant to render the NPVIC invalid. See, e.g., Schleifer, supra note 2, at 740 (expressing doubt that “the destruction of such a remote and highly contingent power” as the presidential selection power of the House of Representatives “would be considered anything but a de minimis encroachment on the federal prerogative[.]”).

1
Gray v. Sanders, 372 U.S. 368, 376 n.8 (1963).
2
Adam Schleifer, Interstate Agreement for Electoral Reform, 40 Akron L. Rev. 717, 720–21 (2007).
3
Thomas H. Neale & Andrew L. Nolan, Cong. Rsch. Serv., R43823, The National Popular Vote (NPV) Initiative: Direct Election of the President by Interstate Compact 1 (2019); see also Schleifer, supra note 2, at 720. The true figure is potentially much higher. Derek Muller’s article, which was written over a decade prior to the CRS report, locates over a thousand failed attempts. Derek T. Muller, The Compact Clause and the National Popular Vote Interstate Compact, 6 Election L. J. 372, 374 (2007) [hereinafter The Compact Clause].
4
U.S. Const. art. V.
5
U.S. Const. amends. I-X; XI-XXVII.
6
John R. Koza et al., Every Vote Equal: A State-Based Plan for Electing the President by National Popular Vote 255–58 (National Popular Vote Press 4th ed. 2013).
7
Schleifer, supra note 2, at 718.
8
Koza et al., supra note 6.
9
U.S. Const. II, § 1.
10
Koza et al., supra note 6, at 275, 723.
11
California (54 electoral votes), Colorado (10 electoral votes), Connecticut (7 electoral votes), Delaware (3 electoral votes), D.C. (3 electoral votes), Hawaii (4 electoral votes), Illinois (19 electoral votes), Maine (4 electoral votes), Maryland (10 electoral votes), Massachusetts (11 electoral votes), Minnesota (10 electoral votes), New Jersey (14 electoral votes), New Mexico (5 electoral votes), New York (28 electoral votes), Oregon (8 electoral votes), Rhode Island (4 electoral votes), Vermont (3 electoral votes), and Washington (12 electoral votes) have all enacted the National Popular Vote bill. State Status, National Popular Vote, https://www.nationalpopularvote.com/state-status (last visited Apr. 2025) [https://perma.cc/TB8N-8VJY]; Neale & Nolan, supra note 3, at 9.
12
News History, National Popular Vote, https://www.nationalpopularvote.com/news-history (last visited Apr. 2025) [https://perma.cc/G3UZ-26YS].
13
Kansas (H.B. 2257), Pennsylvania (H.B. 270), and South Carolina (H. 3870). Election Administration Legislation Tracker, Ballotpedia, https://legislation.ballotpedia.org/elections/search?category=National%20Popular%20Vote%20Interstate%20Compact&session=2025&page=1 (last visited Oct. 28 2025) [https://perma.cc/M5T6-MWMU].
14
U.S. Const. art. II, § 1.
15
See, e.g., Muller, The Compact Clause, supra note 3, at 393.
16
McPherson v. Blacker, 146 U.S. 1, 35 (1892) (unanimous opinion) (“[T]he appointment and mode of appointment of electors belong exclusively to the [s]tates under the Constitution of the United States.”).
17
U.S. Const. art. I, § 10.
18
Jennifer S. Hendricks, Popular Election of the President: Using or Abusing the Electoral College?, 7 Election L. J. 218, 220–224 (2008) (arguing that an alternative, “strong-arm” form of the NPVIC would be a treaty).
19
The NPVIC contains many characteristics common to interstate compacts. Like the Multistate Tax Compact at issue in U.S. Steel, the NPVIC is not effective until a specified threshold of states adopt it, and it contains procedures for withdrawal and termination. Koza et al., supra note 6, at 259–60. Many of the NPVIC’s fiercest advocates emphasize its contract-like quality as its primary benefit: by imbuing signatories with “bind[ing],” “contractual obligations,” the NPVIC guarantees that all of its members will comply with the agreed-upon electoral vote apportionment procedure, regardless of which candidate wins in each individual state. Id. at 207. It would be hard to argue that a binding interstate contract is somehow not also “the formation of [a] combination of states.” Virginia v. Tennessee, 148 U.S. at 519. The NPVIC is almost certainly an “agreement” or “compact” and is therefore not per se exempt from the Compact Clause’s requirements. It is worth noting that whether the NPVIC would be enforceable remains an open question. If a member state violates agreed-upon procedures and decides to apportion its electoral votes to a candidate other than the winner of the nationwide popular vote, what would be the recourse? It seems plausible that the courts would decline to weigh in, citing the political question doctrine. Although the issue of enforcement is outside the scope of this essay, this is an important area for further inquiry before implementing the NPVIC.
20
U.S. Const. art. I, § 10, cl. 3.
21
U.S. Steel Corp. v. Multistate Tax Comm’n, 434 U.S. 452, 460–61 (1978).
22
See Articles of Confederation art. VI.
23
Michael S. Greve, Compacts, Cartels, and Congressional Consent, 68 Mo. L. Rev. 285, 297 (2003).
24
Schleifer, supra note 2, at 729.
25
Id. (quoting The Federalist No. 44, 281 (James Madison) (Clinton Rossiter ed., 1961)).
26
Muller, The Compact Clause, supra note 3, at 379.
27
U.S. Steel, 434 U.S. at 463. See also Muller, The Compact Clause, supra note 3, at 379.
28
Muller, The Compact Clause, supra note 3, at 379.
29
U.S. Steel, 434 U.S. at 459.
30
Virginia v. Tennessee, 148 U.S. 503, 518 (1893).
31
Id. As the above analysis suggests, divinations about the Framers’ intentions for the Compact Clause are on somewhat dubious historical footing.
32
U.S. Steel, 434 U.S. at 462.
33
U.S. Steel, 434 U.S. at 489 (White, J., dissenting). See, e.g., Ian J. Drake, Federal Roadblocks: The Constitution and the National Popular Vote Interstate Compact, 44 Publius: The Journal of Federalism 681, 686 (2013); Greve, supra note 23, at 288; Hendricks, supra note 18, at 220; Muller, The Compact Clause, supra note 3, at 383; Schleifer, supra note 2, at 733, 738.
34
Virginia v. Tennessee, 148 U.S. at 518–521.
35
Schleifer, supra note 2, at 732. See also New Hampshire v. Maine, 426 U.S. 363, 369–70 (1976).
36
Virginia v. Tennessee, 148 U.S. at 520.
37
Id. at 518.
38
Id. at 519.
39
James Madison, Preface to the Debates in the Convention, in Notes of Debate in the Federal Convention of 1787, at 14 (Adrienne Koch ed., Ohio University Press 1984) (“Federal authority was violated . . . by [interstate] compacts without the consent of Congress[.]”).
40
Virginia v. Tennessee, 148 U.S. at 518–19 (stating that only agreements that “tend to increase and build up the political influence of the contracting states” in a way that “encroach[es] upon or impair[s]” federal sovereignty would be constitutionally invalid absent congressional consent).
41
See, e.g., Hendricks, supra note 18, at 224–26.
42
Virginia v. Tennessee, 148 U.S. at 521.
43
Id. at 518.
44
See, e.g., id. at 520 (stating that the inquiry is whether the compact “may lead or not to the increase of the political power or influence of the States affected, and thus encroach or not upon the full and free exercise of Federal authority.”).
45
U.S. Steel, 434 U.S. at 457, 475.
46
Id. at 454.
47
Id. at 460 (“[W]e are reluctant to . . . circumscribe modes of interstate cooperation that do not enhance state power to the detriment of federal supremacy.”).
48
New Hampshire v. Maine, 426 U.S. at 369–70.
49
U.S. Steel, 434 U.S. at 471.
50
Id. at 473. See also id. at 471 (“The relevant inquiry must be one of the impact on our federal structure”), 472 (“[The compact] must be judged in terms of enhancement of state power in relation to the federal government.”).
51
Id. at 473. Hans von Spakovsky has argued that these indicia are prongs of a three-factor test, and the absence of any of the described characteristics is sufficient to subject an interstate compact to the congressional consent requirement. Hans von Spakovsky, Destroying the Electoral College: The Anti-Federalist National Popular Vote Scheme, Heritage Found. (Oct. 27, 2011), https://www.heritage.org/election-integrity/report/destroying-the-electoral-college-the-anti-federalist-national-popular [https://perma.cc/ETB3-QRNT]. This is a misreading of the majority’s opinion. These characteristics do not determine whether a compact requires congressional consent to become effective. The only required consideration that the Court has consistently weighed is whether the stipulation impermissibly enhances state power at the expense of the national government. While these characteristics may guide a court in analyzing an interstate compact, they should not be conflated with necessary conditions of Compact Clause-compatible agreements. A compact may possess all, some, or even none of these characteristics and still be exempted from the Compact Clause’s strictures. See U.S. Steel, 434 U.S. at 472–73 (listing these characteristics as evidence that “[o]n its face [the challenge compact] contains no provisions that would enhance the political power of the member States in a way that encroaches upon the supremacy of the United States”). See also Koza et al., supra note 6, at 642–44.
52
U.S. Steel, 434 U.S. at 473.
53
Id. at 484, 490 (White, J., dissenting).
54
Id. at 479–80 n.33 (“Federal power in the relevant areas remains plenary; no action authorized by the Constitution is ‘foreclosed.’”).
55
Id.
56
Id.
57
Schleifer, supra note 2, at 733.
58
U.S. Steel, 434 U.S. at 493 (White, J., dissenting).
59
Id. at 482, 490–91 (White, J., dissenting) (“[T]he majority has but one repeated answer: that each member State is free to adopt the procedures in question just as it could as if the Compact did not exist[.]”).
60
Id. at 482 (White, J., dissenting).
61
Id.
62
Id. at 494 n.23 (White, J., dissenting).
63
Id. at 477-78.
64
Id. This distinction is discussed in greater detail below.
65
Id. at 479 n.33 (quoting Virginia v. Tennessee, 148 U.S. at 519).
66
Virginia v. Tennessee, 148 U.S. at 518.
67
Muller, The Compact Clause, supra note 3, at 383 (interpreting the test differently, but stating that the Virginia v. Tennessee test “still controls today.”).
68
U.S. Steel, 434 U.S. at 468; see also Hendricks, supra note 18, at 225.
69
U.S. Steel, 434 U.S. at 468–73. See, e.g., New Hampshire v. Maine, 426 U.S. at 369-70; Northeast Bancorp, Inc. v. Bd. of Governors of the Fed. Rsrv. Sys., 472 U.S. 159, 176 (1985) (“We do not see how the statutes in question . . . enhance the political power of the New England states at the expense of other States or have an ‘impact on our federal structure.’”) (emphasis in original).
70
U.S. Const. art. I, § 10, cl. 3.
71
Muller, The Compact Clause, supra note 3, at 390; Schleifer, supra note 2, at 734.
72
Muller, The Compact Clause, supra note 3.
73
See, e.g., Thomas Jipping, The National Popular Vote: Misusing an Interstate Compact to Bypass the Constitution, Heritage Found. 4 n.34, 9 n.64 (Oct. 8, 2020), https://www.heritage.org/civil-rights/report/the-national-popular-vote-misusing-interstate-compact-bypass-the-constitution [https://perma.cc/Z76Q-V3PL] (citing Muller in support of the argument that the NPVIC requires congressional consent); Neale & Nolan, supra note 3, at 26 n.158–59 (discussing Muller’s arguments that the NPVIC requires congressional consent due to horizontal federalism concerns); Wikipedia, Constitutionality of the National Popular Vote Interstate Compact, https://en.wikipedia.org/wiki/Constitutionality_of_the_National_Popular_Vote_Interstate_Compact [https://perma.cc/MGL2-UH8P] (last visited Sept. 28, 2025) (citing Muller as one “legal commentator[] [who] ha[s] argued that the power of non-compacting states would be altered” by the NPVIC); Derek T. Muller, The Electoral College and the Federal Popular Vote, 15 Harv. L. & Pol’y Rev. 129, 143 n.73 (2020) (citing his prior articles challenging the constitutionality of the NPVIC in an article that advances other arguments against the NPVIC beyond constitutional critiques).
74
Muller, The Compact Clause, supra note 3, at 377.
75
U.S. Steel, 434 U.S. at 473.
76
Professor Muller’s original article does not directly define “political” and “non-political.” See Hendricks, supra note 18, at 225. Professor Jennifer S. Hendricks argues that Muller’s categorical approach obscures and “simplif[ies]” the Court’s actual test by relocating the focus from the compact’s effect to its topic. Hendricks, supra note 18, at 225. If a compact involves “political” matters, like elections, then it would automatically require congressional consent, regardless of whether it in fact encroaches on federal supremacy. Id. In response to this criticism, Muller clarified that, while not all compacts implicating political issues necessarily require congressional consent, the NPVIC would because of its effect on “political power,” defined as “the capacity to influence the activities of the body politic.” Muller, More Thoughts on the Compact Clause and the National Popular Vote: A Response to Professor Hendricks, 7 Election L. J. 227, 230 (2008) [hereinafter More Thoughts] (quoting Black’s Law Dictionary 1197 (8th ed. 2004)).
77
See, e.g., Virginia v. Tennessee, 148 U.S. 503; U.S. Steel, 434 U.S. 452; Northeast Bancorp, 472 U.S. 159. Muller located his “political”/“non-political” framing in the Court’s attention to “political power” in its Compact Clause analyses. Muller, More Thoughts, supra note 76, at 229.
78
See, e.g., Virginia v. Tennessee, 148 U.S. at 520-21 (weighing the particular features of the challenged compact); U.S. Steel, 434 U.S. at 472–76 (same); Northeast Bancorp, 472 U.S. at 175–76 (same).
79
Muller, More Thoughts, supra note 76, at 230.
80
U.S. Steel, 434 U.S. at 468. See also Greve, supra note 23 at 368–76 (discussing the “functional” test for congressional consent); Hendricks, supra note 18, at 225 (noting U.S. Steel’s “functional” test); Schleifer, supra note 2, at 733 (“[T]he Court . . . confirmed the functional test set out [in Virginia v. Tennessee.]”).
81
Muller, The Compact Clause, supra note 3, at 377, 390.
82
Id. at 392.
83
Id. at 385-86.
84
Id. at 385.
85
See Drake, supra note 33, at 689 (“[T]he Compact Clause’s standard is whether federal supremacy is threatened by an ‘encroachment or interference through enhanced state power[.]’”) (quoting U.S. Steel, 434 U.S. at 480 n. 33); Greve, supra note 23 at 285 (acknowledging that U.S. Steel holds that “[the Compact] Clause applies only to state compacts that ‘encroach’ upon federal supremacy” but arguing that the case was “wrongly decided”); Hendricks, supra note 18, at 224–25 (articulating the Virginia v. Tennessee/U.S. Steel test as “whether [a compact] increases state power at the expense of national supremacy”).
86
See Virginia v. Tennessee, 148 U.S. at 518–21.
87
See Muller, The Compact Clause, supra note 3, at 385–86. Muller points to Northeast Bancorp v. Board of Governors as another example of this phenomenon. According to Muller, although the Northeast Bancorp Court rejected the state interest concern as insufficient to bring the challenged stipulation within the ambit of the Compact Clause, the fact that it weighed that consideration at all is proof of its existence. Id. at 387. This evidence is unpersuasive. In Northeast Bancorp, the Court declined to determine whether the interstate action at issue amounted to a “compact” or “agreement” within the Compact Clause. Instead, in response to petitioner’s allegation that the challenged conduct “impermissibly offends the sovereignty of sister States,” the Court declared dismissively and simply that, “We do not see how the statutes in question either enhance the political power of the New England States at the expense of other States or have an ‘impact on our federal structure,’” quoting U.S. Steel. Northeast Bancorp, 472 U.S. at 176.
88
Muller, The Compact Clause, supra note 3, at 386.
89
Just not the Multistate Tax Compact. Id. at 387.
90
U.S. Steel, 434 U.S. at 477–78 (“[E]ven if” the compact did “redound to the benefit of any particular group of [s]tates or to the harm of others,” that alone would not be sufficient to implicate the Compact Clause.)
91
Id. at 477.
92
Id. at 478.
93
The two are almost certainly not equivalent, given the Court’s careful distinction between “federal interest” and “federal supremacy.” U.S. Steel, 434 U.S. at 479 n.33.
94
See id. at 478. The Court pointed to the Commerce Clause and the Privileges and Immunities Clause, as the Multistate Tax Compact implicated these federal powers. Id.
95
Muller, The Compact Clause, supra note 3, at 392. Notably, there is disagreement among scholars on this point. Professor Hendricks seems sympathetic to Professor Muller’s emphasis on non-compacting states, whereas Schleifer seems more aligned with my understanding. Hendricks, supra note 18, at 225 (“[T]he majority of the Court was willing to tolerate coordinated state action to achieve otherwise unattainable goals, so long as the sovereign rights of other states remained intact.”); Schleifer, supra note 2, at 731 (“The Court here seems to ask whether the power of the states is altered, but only as a proxy for how the states are affected in their relationship to the federal government.”).
96
Id. at 386 (“[T]he sister state interest of the Compact Clause [is] most lucidly stated in Justice White’s dissent[.]”). See also id. at 389.
97
U.S. Steel, 434 U.S. at 494 (White, J., dissenting) (expressing dismay over the majority’s inattentiveness to state interests).
98
Muller, More Thoughts, supra note 76, at 228. Ian Drake points to Cuyler v. Adams (1981), in which the Court cited White’s dissent “with approval,” to buttress the persuasive authority he and Muller ascribe to it. Drake, supra note 33, at 690. However, the Cuyler Court invoked White’s language about factors that Congress, not the courts, takes into account when making the “political judgment” of whether to approve a compact, which is inapplicable to Muller’s “sister state” interest test. See 449 U.S. 433, 440 n.8 (1981).
99
Muller, More Thoughts, supra note 76, at 228.
100
U.S. Steel, 434 U.S. at 473.
101
Hendricks, supra note 18, at 225 (discussing Muller, The Compact Clause, supra note 3, at 385–87). Professor Michael Greve, whom Muller cites, raises a similar argument. Greve, supra note 23, at 301. See also Schleifer, supra note 2, at 731, 740–41.
102
Virginia v. Tennessee, 148 U.S. at 517–21, 525 (announcing the Court’s modern interpretation of the Commerce Clause despite holding that Congress had impliedly consented to the challenged compact at issue, rendering it unnecessary for the Court to determine when congressional consent is required).
103
U.S. Steel, 434 U.S. at 479 n.33 (addressing the dissent’s concerns about federal interests at length but apparently ignoring the dissent’s concerns about state interests).
104
Schleifer, supra note 2, at 733 (“[T]he Court . . . indicated unmistakably that it is vertical, and not horizontal issues of state power that are relevant to the inquiry regarding consent[.]”).
105
Virginia v. Tennessee, 148 U.S. at 518.
106
Muller, The Compact Clause, supra note 3, at 388.
107
Neale & Nolan, supra note 3, at 23.
108
Virginia v. Tennessee, 148 U.S. at 519.
109
U.S. Steel, 434 U.S. at 470–71; Virginia v. Tennessee, 148 U.S. at 520.
110
Virginia v. Tennessee, 148 U.S. at 520.
111
U.S. Steel, 434 U.S. at 472.
112
Id. at 473.
113
See Drake, supra note 33, at 686.
114
Muller, The Compact Clause, supra note 3, at 391–92.
115
Muller, The Compact Clause, supra note 3, at 391; see also Drake, supra note 33, at 687.
116
Muller, The Compact Clause, supra note 3, at 393.
117
Hendricks, supra note 18, at 225.
118
U.S. Const. art. II, § 1, cl. 2.
119
McPherson, 146 U.S. at 24, 35 (upholding scheme determining the state’s chosen candidate according to the winner from each congressional district, as opposed to a state-wide popular vote). Because the Electoral College is zero sum, enhancing the worth of one state diminishes the worth of the others.
120
48 states and D.C. employ the winner-take-all method. Hendricks, supra note 18, at 219.
121
Koza et al., supra note 6, at 637–38.
122
Both Maine and Nebraska have different systems. Hendricks, supra note 18, at 219.
123
Katherine Florey, Losing Bargain: Why Winner-Take-All Vote Assignment is the Electoral College’s Least Defensible Feature, 68 Case W. Rsrv. L. Rev. 317, 345–60 (2017).
124
See Williams v. Va. State Bd. of Elections, 288 F. Supp. 622, 628–29 (E.D. Va. 1968), aff’d, 393 U.S. 320 (1969) (per curiam).
125
Muller, The Compact Clause, supra note 3, at 391.
126
Muller, More Thoughts, supra note 76, at 231–32 (“It is not a bare power to appoint electors qua electors sine potente; it is a power to appoint electors whose role is to elect the President.”).
127
See Hendricks, supra note 18, at 226.
128
Muller, More Thoughts, supra note 76, at 231.
129
Id.
130
U.S. Steel, 434 U.S. at 472; Virginia v. Tennessee, 148 U.S. at 519.
131
U.S. Steel, 434 U.S. at 473 (upholding the challenged compact because, among other reasons, “[it] does not purport to authorize the member States to exercise any powers they could not exercise in its absence”); U.S. Const. amend. X.
132
U.S. Const. art. II, § 1, cl. 2.
133
U.S. Steel, 434 U.S. at 473.
134
Virginia v. Tennessee, 148 U.S. at 518; U.S. Const. art. II, § 1, cl. 2.
135
McPherson, 146 U.S. at 35.
136
U.S. Const. art. I, § 8, cl. 1, 3.
137
U.S. Steel, 434 U.S. at 472–73.
138
Muller, The Compact Clause, supra note 3, at 390. Some scholars have argued that the NPVIC implicates “federal interests” sufficient to bring it within the ambit of the Compact Clause, including protecting the constitutional amendment process, the stability and preservation of the Electoral College, and the power vested in the House of Representatives to select the president if the Electoral College fails. Tara Ross, Federalism & Separation of Powers: Legal and Logistical Ramifications of the National Popular Vote Plan, 11 The Federalist Soc’y 40 (2010); Drake, supra note 33, at 684; Schleifer, supra note 2, at 739–40. While these interests may exist, mere existence of a “federal interest” is not equivalent to an interference with “federal sovereignty,” as U.S. Steel makes clear. U.S. Steel, 434 U.S. at 479 n.33. Because only infringements on national sovereignty implicate the Compact Clause, these identified interests are likely not sufficiently significant to render the NPVIC invalid. See, e.g., Schleifer, supra note 2, at 740 (expressing doubt that “the destruction of such a remote and highly contingent power” as the presidential selection power of the House of Representatives “would be considered anything but a de minimis encroachment on the federal prerogative[.]”).