Supremacy Clause

Original public meaning

The Convention's first mechanism for federal supremacy was not a supremacy clause at all but a congressional veto over state law. Madison's 29 May 1787 resolution proposed the National Legislature be empowered "to negative all laws passed by the several States, contravening in the opinion of the National Legislature the articles of Union." Charles Pinckney pushed to make the negative universal — "authority to negative all Laws which they shd. judge to be improper" — and Madison defended it as indispensable:

"Experience had evinced a constant tendency in the States to encroach on the federal authority; to violate national Treaties, to infringe the rights & interests of each other. ... A negative was the mildest expedient that could be devised for preventing these mischiefs." — Records of the Federal Convention, 8 June 1787

The congressional negative was voted down, and the Committee of Detail substituted the declaratory approach that became Article VI: rather than empowering Congress to veto state law case by case, the Constitution itself, federal law made pursuant to it, and treaties were simply declared supreme, leaving enforcement to the courts (state and federal) rather than to a legislative check.

Confederation-era antecedent: the Pennsylvania passport dispute, January 1783

Four years before the Convention wrote a supremacy clause, the Confederation Congress and a state government fought the same question in practice: whether a state law can stand against the exercise of a power the states had already delegated to Congress. Elliot's Debates (Vol. V) preserves the episode. A Continental passport had authorized British and German prisoner-of-war supplies to pass overland through Pennsylvania; Chester County residents seized the cargo under a Pennsylvania law requiring executive license for such shipments. Congress read the seizure as a state law overriding an exercise of the delegated war power, and a conference committee (Rutledge, Wolcott, Madison) told Pennsylvania's own executive and legislative committee so directly:

"The committee observed to them, that the power of granting passports for the purpose in question being inseparable from the general power of war delegated to Congress, and being essential for conducting the war, it could not be expected that Congress would acquiesce in any infractions upon it; that as Pennsylvania had concurred in the alienation of this power to Congress, any law whatever contravening it was necessarily void, and could impose no obligation on the executive." — conference committee (Rutledge, Wolcott, Madison), Congress of the Confederation, 24 Jan. 1783

A Pennsylvania legislator, Mr. Montgomery, pressed the counter-argument later ratifying conventions would call concurrent or reserved state power — that a state could regulate how a delegated federal power operated, so long as it did not "frustrate" the power itself:

"Mr. Montgomery, lately a member of Congress, observed that, although the general power of war was given to Congress, yet that the mode of exercising that power might be regulated by the states in any manner which would not frustrate the power, and which their policy might require." — Mr. Montgomery, Pennsylvania legislative committee, 24 Jan. 1783

The Congressional committee rejected that middle ground outright, arguing any state check on a delegated power — however narrow — collapses into a veto over the whole:

"To this it was answered, that if Congress had the power at all, it could not, either by the Articles of Confederation or the reason of things, admit of such a controlling power in each of the states; and that to admit such a construction would be a virtual surrender to the states of their whole federal power relative to war, the most essential of all the powers delegated to Congress." — conference committee (Rutledge, Wolcott, Madison), Congress of the Confederation, 24 Jan. 1783

The dispute resolved not by a ruling but by diplomacy: Pennsylvania's executive and legislature could not repeal the law without a constitutionally barred retrospective act, so the parties induced the private seizors to petition Congress directly for a negotiated referee process, which Congress granted. Madison's own narration credits Pennsylvania's president, John Dickinson, with managing the compromise in good faith: he "manifested throughout the course of it, as great a desire to save the rights and dignity of Congress, as those of the state over which he presided."

key-insight

The committee's "necessarily void" language is a pre-constitutional statement of the Supremacy Clause's operative principle — that state law contrary to a validly delegated federal power has no legal force — reached by political argument between a Congress and a state's own executive, four years before Article VI made the same conclusion self-executing text enforced by courts. Unlike the ratifying-convention debates below, no one here disputes that Congress has the war power; the fight is entirely over whether a state may condition or channel that power's exercise once delegated — the same question Montgomery's "would not frustrate" test poses against the committee's "no controlling power at all" answer.

A second Confederation-era antecedent: treaties as "law of the land," six weeks before the Convention opened

The Pennsylvania passport dispute (above) tested a delegated power — war — against a contrary state law. A second episode, argued in Congress in March 1787 while the Annapolis-called Convention was already six weeks from convening, tested the different half of Article VI cl. 2's eventual text: whether a treaty already had the force of law binding state courts and state legislation on its own, without any further act of ratification by the states. Elliot's Debates (Vol. V) preserves Madison's diary of the debate over Secretary of Foreign Affairs John Jay's report on enforcing the 1783 Treaty of Paris. Mr. Yates of New York objected to the report's first resolution outright:

"Mr. YATES objected to the first resolution, which declares the treaty to be a law of the land. He said the states, or at least his state, did not admit it to be such until clothed with legal sanction." — Mr. Yates, Congress of the Confederation, 20 March 1787

Yates was answered, and satisfied, the next day — not by abandoning the "law of the land" claim, but by a qualifying word already doing the same work Article VI cl. 2's own "in Pursuance thereof" would later do for federal statutes:

"Mr. YATES was now satisfied with the resolutions as they stood. The words 'constitutionally made,' as applied to the treaty, seemed to him, on consideration, to qualify sufficiently the doctrine on which the resolution was founded." — Mr. Yates, Congress of the Confederation, 21 March 1787

The harder question was whether a treaty could do more than repeal state laws that predated it — whether it could void state laws passed afterward, in conflict with it. Mr. Varnum and Mr. Mitchell argued the premise was self-contradictory: if such laws were already "void," they could not simultaneously be described as "operating" in violation of the treaty. James Madison's answer is the wiki's clearest founding-era statement, prior to the Convention itself, of the exact question Article VI cl. 2 would later settle by declaring federal supremacy self-executing rather than dependent on state legislative repeal:

"Supposing the treaty to have the validity of a law only, it would repeal all antecedent laws. To render succeeding laws void, it must have more than the mere authority of a law. In case these succeeding laws, contrary to the treaty, should come into discussion before the courts, it would be necessary to examine the foundation of the federal authority, and to determine whether it had the validity of a constitution paramount to the legislative authority in each state. This was a delicate question, and studiously to be avoided, as it was notorious that, although in some of the states the Confederation was incorporated with, and had the sanction of, their respective constitutions, yet in others it received a legislative ratification only, and rested on no other basis." — James Madison, Congress of the Confederation, 21 March 1787

Madison proposed replacing "operate" with "be regarded" as violations of the treaty — a wording change adopted without opposition that let Congress avoid deciding, in March 1787, the very question the Convention would answer five months later by writing "supreme Law of the Land" directly into the text Madison here calls "delicate." Mr. King raised a further, narrower question the resolutions left open — whether treaty stipulations affecting only citizens, not foreigners, could bind the states at all — and supposed they could not. The resolutions, as qualified, passed unanimously.

key-insight

Madison's own words here — a treaty might need "the validity of a constitution paramount to the legislative authority in each state" to bind state courts against later state laws — is close enough to Article VI cl. 2's actual operative language ("supreme Law of the Land... any Thing in the Constitution or Laws of any State to the Contrary notwithstanding") that this March 1787 floor debate reads as a direct rehearsal of the clause the Committee of Detail would draft that August. Madison calls the question "delicate, and studiously to be avoided" — under the Confederation, Congress could finesse it with a wording change ("be regarded" for "operate"); under the Constitution, the Convention resolved it outright by declaratory text rather than leaving it, as Congress did here, for courts to confront case by case. Unlike the Pennsylvania passport dispute's live power struggle (above), no one in this debate disputes that treaties should bind states in some fashion — the fight is over whether the existing Confederation, without a supremacy clause, already achieves that result or merely gestures at it.

A textual ancestor: the New Jersey Plan's own supremacy clause

The declaratory approach was not invented by the Committee of Detail in August as a fallback once the negative failed. Patterson's New Jersey Plan — the small-state counter-proposal tabled 15 June 1787, five weeks before Randolph's negative was struck — already contained a complete, freestanding supremacy clause as its own seventh resolution, proposed as the small states' preferred mechanism from the outset rather than as a substitute chosen only after the negative's defeat:

"Resolved, That all acts of the United States in Congress assembled, made by virtue and in pursuance of the powers hereby vested in them, and by the Articles of Confederation, and all treaties made and ratified under the authority of the United States, shall be the supreme law of the respective states as far as those acts or treaties shall relate to the said states, or their citizens; and that the judiciaries of the several states shall be bound thereby in their decisions, any thing in the respective laws of the individual states to the contrary notwithstanding." — Patterson's Propositions, Res. 7, 15 June 1787, quoted in Elliot's Debates vol. 1

The parallel to the enacted text is close enough to be more than coincidental: "supreme law," judges "bound thereby," and an express override of contrary state law all appear in Patterson's Resolution 7 in nearly the same sequence Article VI cl. 2 uses. Charles Pinckney's rival draft, tabled the same day, independently proposed a narrower version confined to acts "pursuant to this constitution" (see National Legislative Negative for Pinckney's accompanying revise-and-annul power). Neither small-state plan's version of supremacy was adopted as such — the enacted clause descends from the Committee of Detail's own drafting — but both show that declaratory federal supremacy was on the Convention floor as a competing design against Randolph's negative from mid-June onward, not a consolation prize devised only after 17 July.

key-insight

This complicates the "negative struck, supremacy substituted" narrative above in a useful way: the substitute was not new in August. The Convention spent two months with a congressional negative (Virginia Plan) and a judicial-supremacy clause (New Jersey Plan) on the table simultaneously, representing large-state and small-state preferences respectively, before choosing the small-state mechanism while keeping the large-state (proportional, national) legislature. The Constitution's structure and its supremacy mechanism came from opposite sides of the same fight.

The negative's defeat and the substitute's adoption, back to back on 17 July

The Convention's own Journal shows the substitution happening within a single session, not across a gap the New Jersey Plan's earlier text merely anticipated. The house voted down the national negative:

"On the question to agree to the following clause of the 6th resolution . . . 'to negative all laws passed by the several states contravening, in the opinion of the national legislature, the articles of union, or any treaties subsisting under the authority of the Union,' — it passed in the negative." Yeas: Massachusetts, Virginia, North Carolina, 3. Nays: Connecticut, New Jersey, Pennsylvania, Delaware, Maryland, South Carolina, Georgia, 7. — Journal of the Federal Convention, 17 July 1787, quoted in Elliot's Debates vol. 1

Then, immediately, without recorded debate in between, adopted the supremacy resolution unanimously:

"Resolved, That the legislative acts of the United States, made by virtue and in pursuance of the articles of union, and all treaties made and ratified under the authority of the United States, shall be the supreme law of the respective states, as far as those acts, or treaties, shall relate to the said states, or their citizens and inhabitants; and that the judiciaries of the several states shall be bound thereby in their decisions, any thing in the respective laws of the individual states to the contrary notwithstanding." It passed unanimously in the affirmative. — Journal of the Federal Convention, 17 July 1787, quoted in Elliot's Debates vol. 1

This 17 July resolution still speaks of laws made "in pursuance of the articles of union" — the Confederation, not yet a constitution that did not exist. The Committee of Detail's own first draft, reported three weeks later on 6 August, restates the clause with the word that would carry into the ratified text:

"The acts of the legislature of the United States made in pursuance of this Constitution, and all treaties made under the authority of the United States, shall be the supreme law of the several states, and of their citizens and inhabitants; and the judges in the several states shall be bound thereby in their decisions; any thing in the constitutions or laws of the several states to the contrary notwithstanding." — Draft of a Constitution, Art. VIII, 6 Aug. 1787, quoted in Elliot's Debates vol. 1

The shift from "articles of union" to "this Constitution" tracks the enacted Art. VI cl. 2's own "in Pursuance thereof" almost exactly — a small drafting change with a large referent: by 6 August the Committee of Detail was drafting for a freestanding Constitution, not an amended Confederation, even though the Convention's own chartering mandate (see Ratification Clause) still spoke only of "revising" the Articles.

Madison's own Notes: the floor argument behind the 17 July votes, and Luther Martin's own authorship of the supremacy resolution

The Journal excerpts above (17 July) preserve two bare tallies — the negative's 3-7 defeat, the supremacy resolution's unanimous adoption — with no debate and no named mover for the second. Madison's own Notes on the Convention supply both. Gouverneur Morris opposed the negative as "likely to be terrible to the states, and not necessary if sufficient legislative authority should be given to the general government." Sherman thought it unnecessary on a narrower ground — that state courts "would not consider as valid any law contravening the authority of the Union, and which the legislature would wish to be negatived." Luther Martin called the power "improper and inadmissible," asking directly: "Shall all the laws of the states be sent up to the general legislature before they shall be permitted to operate?" Madison answered with the debate's fullest defense of the negative, grounding it not in an abstract federal-supremacy theory but in a specific, named distrust of state judiciaries as guardians of national authority:

"Confidence cannot be put in the state tribunals as guardians of the national authority and interests. In all the states, these are more or less dependent on the legislatures. In Georgia, they are appointed annually by the legislature. In Rhode Island, the judges who refused to execute an unconstitutional law were displaced; and others substituted, by the legislature, who would be the willing instruments of the wicked and arbitrary plans of their masters. A power of negativing the improper laws of the states is at once the most mild and certain means of preserving the harmony of the system. Its utility is sufficiently displayed in the British system. Nothing could maintain the harmony and subordination of the various parts of the empire, but the prerogative by which the crown stifles in the birth every act of every part tending to discord or encroachment." — James Madison, Notes on the Convention, 17 July 1787

Gouverneur Morris answered that a bad state law "will be set aside in the judiciary department, and, if that security should fail, may be repealed by a national law" — pointing to the alternative Article VI's declaratory approach would in fact adopt. Sherman repeated that the negative wrongly presupposed a contrary state law would otherwise be "valid and operative" absent a veto. Pinckney alone spoke for the negative's "necessity" without elaboration. The negative failed, 3-7 (Massachusetts, Virginia, North Carolina only) — the same tally already quoted from the Journal above, now with the argument behind it.

Immediately afterward, in the same session, Luther Martin — not an anonymous Journal "Resolved," but Martin named by Madison — moved the resolution that became this clause:

"Mr. L. MARTIN moved the following resolution: — 'That the legislative acts of the United States, made by virtue and in pursuance of the Articles of Union, and all treaties made and ratified under the authority of the United States, shall be the supreme law of the respective states, as far as those acts or treaties shall relate to the said states, or their citizens and inhabitants; and that the judiciaries of the several states shall be bound thereby in their decisions, any thing in the respective laws of the individual states to the contrary notwithstanding.' Which was agreed to, nem. con." — James Madison, Notes on the Convention, 17 July 1787

key-insight

This resolves an attribution gap the Journal excerpt above leaves open: the Supremacy Clause's own textual ancestor was moved by Luther Martin — the same delegate who, minutes earlier in the same session, argued against the congressional negative on the ground that it would let the general government second-guess every state law before it could "operate." Martin did not merely help defeat the negative; he supplied its declaratory replacement himself, on the floor, the same day — corroborating this page's earlier observation (above, "A textual ancestor: the New Jersey Plan's own supremacy clause") that declaratory supremacy was the small-state position throughout, not a fallback the large states settled for only after their own preferred mechanism failed.

Hamilton's *Federalist* No. 33 treats the clause as adding nothing beyond what "law" already means:

"A LAW by the very meaning of the term includes supremacy. ... It will not, I presume, have escaped observation that it expressly confines this supremacy to laws made pursuant to the Constitution; which I mention merely as an instance of caution in the Convention; since that limitation would have been to be understood though it had not been expressed." — Alexander Hamilton, Federalist No. 33 (2 Jan. 1788)

Madison's *Federalist* No. 44 makes the counterfactual explicit — a Constitution that left state constitutions fully "supreme" over federal law "would have been evidently and radically defective":

"The world would have seen for the first time, a system of government founded on an inversion of the fundamental principles of all government; it would have seen the authority of the whole society every where subordinate to the authority of the parts; it would have seen a monster in which the head was under the direction of the members." — James Madison, Federalist No. 44 (25 Jan. 1788)

Story's Commentaries echoes Hamilton nearly verbatim on the "law includes supremacy" point and extends it to treaties specifically, holding that without judicially enforceable supremacy, treaty obligations reduce to unenforceable moral compacts — precisely the failure mode the Confederation had already suffered:

"It is notorious, that treaty stipulations (especially those of the treaty of peace of 1783) were grossly disregarded by the states under the confederation. They were deemed by the states, not as laws, but like requisitions, of mere moral obligation." — Joseph Story, Commentaries on the Constitution 3:§ 1832 (1833)

Pennsylvania convention: M'Kean's floor concession

Thomas M'Kean's closing speech to the Pennsylvania convention answered the Supremacy Clause objection together with the Necessary and Proper Clause objection, treating both as resolved by the same reasoning (see Necessary and Proper Clause for the fuller context of the pairing):

"[T]his has at last been conceded, that, though it is explicit enough, yet it gives to Congress no further powers than those already enumerated." — Thomas M'Kean, Pennsylvania Convention, 11 Dec. 1787

M'Kean's answer reads the Supremacy Clause exactly as Hamilton's *Federalist* No. 33 and Story's Commentaries do above — supremacy runs only to federal law "made in pursuance" of the Constitution's enumerated grants, not to an independent or expanded federal power. See Elliot's Debates (Vol. II).

George Mason before the Virginia convention: the clause reads the state's own bill of rights out of existence

George Mason's 11 June 1788 speech to the Virginia convention is the wiki's first ratifying-convention floor source to read Art. VI cl. 2 into the record verbatim, and the first to press it specifically against a state's own bill of rights rather than against ordinary state legislation:

"Let us advert to the 6th article. It expressly declares, that 'this Constitution, and the laws of the United States which shall be made in pursuance thereof, and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land, and the judges in every state shall be bound thereby; any thing in the Constitution or laws of any state to the contrary notwithstanding.' Now, sir, if the laws and Constitution of the general government, as expressly said, be paramount to those of any state, are not those rights with which we were afraid to trust our own citizens annulled and given up to the general government?" — George Mason, Virginia Convention, 11 June 1788

Mason — himself the drafter of the Virginia Declaration of Rights — argued the clause extinguishes that document by implication rather than by any express repeal, and that no textual security remains once federal law is declared paramount:

"The bill of rights is a part of our own Constitution. The judges are obliged to take notice of the laws of the general government; consequently, the rights secured by our bill of rights are given up. If they are not given up, where are they secured? By implication! Let gentlemen show that they are secured in a plain, direct, unequivocal manner. It is not in their power. Then where is the security?" — George Mason, Virginia Convention, 11 June 1788

key-insight

Mason's argument is the clause's own bill-of-rights objection stated at the source, months before ratification and independently of the missing-federal-bill-of-rights objection this wiki holds from other founders. Mason does not argue the new Constitution merely lacks a bill of rights (the general Anti-Federalist complaint); he argues the Supremacy Clause affirmatively voids a state's existing one by implication — a reading neither Hamilton's Federalist No. 33 nor Story's Commentaries (both above) addresses directly, since both defend the clause's reach over ordinary state statutes, not over a state's own constitutional guarantees.

The North Carolina convention: sovereignty, paper money, and the word "pursuance" (29 July 1788)

Where George Mason's Virginia-convention objection (above) reads the clause as annulling a state's own bill of rights, the North Carolina convention's debate on the same clause centers on two different fears: that federal supremacy dissolves state sovereignty outright, and that it retroactively destroys state paper currency already in circulation. James Iredell opened by reading the clause as an execution mechanism rather than an expansion of power: "as we have given power, we will support the execution of it? We should act like children, to give power and deny the legality of executing it." Thomas Bloodworth rejected the reassurance in the sharpest sovereignty-annihilation language this wiki holds from any ratifying convention on this clause:

"It appears to me to sweep off all the constitutions of the states. It is a total repeal of every act and constitution of the states. The judges are sworn to uphold it. It will produce an abolition of the state governments. Its sovereignty absolutely annihilates them." — Thomas Bloodworth, North Carolina Convention, 29 July 1788

Iredell answered that the clause reaches only laws made in the execution of a power the Constitution actually grants, leaving "the sufficiency or extent of the power" itself a separate question. Bloodworth, unpersuaded, pivoted the same objection onto North Carolina's own currency: "Is not the force of our tender-laws destroyed by it?"

Archibald Maclaine answered the sovereignty objection structurally — that a law of the Union not binding on every state "would be to give the general government no powers at all" — then took up the paper-money fear directly, reading the state bills-of-credit ban as prospective only:

"The clause cannot possibly have a retrospective view. It cannot affect the existing currency in any manner, except to enhance its value by the prohibition of future emissions." — Archibald Maclaine, North Carolina Convention, 29 July 1788

William R. Davie, a Federal Convention delegate, gave the fullest defense of the same prospective reading, with a specific Rhode Island depreciation history distinct from any register already on State Treaty, Coinage, and Contracts Clause:

"In Rhode Island, the paper money had depreciated to eight for one, and a hundred per cent. with us. The people of Massachusetts and Connecticut had been great sufferers by the dishonesty of Rhode Island... The clause was, I believe, unanimously assented to: it has only a future aspect, and can by no means have a retrospective operation." — William R. Davie, North Carolina Convention, 29 July 1788

Mr. Cabarrus pressed the same point from the Ex Post Facto Clause's own text — a retrospective reading of the state bills-of-credit ban would itself be "ex post facto, and repugnant to the express provision of the Constitution" — and Bloodworth asked directly whether a federal-court judgment against a North Carolina debtor could still be satisfied in paper money; Iredell answered yes, "there being nothing in the Constitution taking away the validity of it." Bloodworth then turned to a sectional-weight objection distinct from the currency question — that thirty-six Northern representatives would permanently outvote twenty-nine Southern ones — which Iredell answered with a state-by-state electoral count showing Pennsylvania's eight votes as the genuine swing bloc rather than a fixed Northern majority.

David Caldwell closed the range's substantive objections with a construction argument new to this wiki's Supremacy Clause record, naming the clause's own operative word as its central defect:

"The word pursuance is equivocal and ambiguous; a plainer word would be better. They may pursue bad as well as good measures, and therefore the word is improper; it authorizes bad measures." — David Caldwell, North Carolina Convention, 29 July 1788

Gov. Samuel Johnston answered that no better word existed to express the idea, and rejected Caldwell's corollary — that Congress's laws, once passed, become as unalterable as the Constitution itself — as resting on no textual basis: "I do not know a more expressive or a better way of representing the idea by words... Are laws as immutable as constitutions? Can any thing be more absurd than assimilating the one to the other?"

key-insight

This range gives the wiki a second ratifying-convention register on the Supremacy Clause distinct from Mason's Virginia bill-of-rights objection (above): North Carolina's Federalists and Anti-Federalists fought less over what the clause does to a state's existing legal guarantees than over what it does to a state's existing legal obligations already in progress — a currently circulating paper currency and pending debts — and over whether "pursuance" itself is precise enough to cabin the power the clause declares supreme.

South Carolina legislature, 16-17 January 1788: Lowndes reads the clause verbatim against Henry VIII, and Pinckney answers with Blackstone, Vattel, and Burlamaqui

South Carolina's House of Representatives — sitting as the Legislature to debate calling a ratifying convention, not yet the convention itself — reached this clause five months before Mason's Virginia-convention floor speech (above), making Hon. Rawlins Lowndes's reading the wiki's earliest ratifying-era floor quotation of Art. VI cl. 2. Where Mason's objection targets the clause's effect on a state's own bill of rights, Lowndes's targets the treaty-and-quorum combination directly, quoting the clause in full before comparing the power it gives ten senators and a President to England's most notorious assertion of unchecked prerogative legislation:

"This Constitution, and the laws of the United States which shall be made in pursuance thereof, and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby — any thing in the Constitution or laws of any state to the contrary notwithstanding." — Art. VI cl. 2, read by Hon. Rawlins Lowndes, South Carolina House of Representatives, 16 Jan. 1788

"Now, in the history of the known world, was there an instance of the rulers of a republic being allowed to go so far? Even the most arbitrary kings possessed nothing like it. The tyrannical Henry VIII. had power given him by Parliament to issue proclamations that should have the same force as laws of the land; but this unconstitutional privilege had been justly reprobated and exploded." — Hon. Rawlins Lowndes, South Carolina House of Representatives, 16 Jan. 1788

Lowndes tied the objection to a specific local consequence distinct from any register already on this page — that the clause, by giving the 1783 peace treaty force as supreme law, would extinguish South Carolina's own debtor-relief instalment law: "he observed, that the clause entirely did away the instalment law; for, when this Constitution came to be established, the treaty of peace might be pleaded against the relief which that law afforded."

Gen. Charles Cotesworth Pinckney answered the next day with the fullest law-of-nations defense of treaty supremacy this wiki holds from any ratifying-era floor source, reading three authorities into the record in succession — Blackstone on the English Crown's own unchecked treaty prerogative, then Vattel and Burlamaqui on why treaties bind a nation's own subjects as law regardless of that nation's domestic constitutional structure:

"[I]t is the king's prerogative to make treaties, leagues, and alliances, with foreign states and princes, and that no other power in the kingdom can legally delay, resist, or annul them." — William Blackstone, Commentaries bk. i ch. 7, p. 257, quoted by Gen. Charles Cotesworth Pinckney, South Carolina House of Representatives, 17 Jan. 1788

"There would be no more security, no longer any commerce between mankind, did they not believe themselves obliged to preserve their faith, and to keep their word. Nations, and their conductors, ought, then, to keep their promises and their treaties inviolable." — Vattel, quoted by Gen. Charles Cotesworth Pinckney, South Carolina House of Representatives, 17 Jan. 1788

"[T]reaties are obligatory on the subjects of the powers who enter into treaties; they are obligatory as conventions between the contracting powers; but they have the force of law with respect to their subjects." — Burlamaqui, quoted by Gen. Charles Cotesworth Pinckney, South Carolina House of Representatives, 17 Jan. 1788

Pinckney argued the enacted clause changed nothing about treaties' domestic legal force — it was "only declaratory of what treaties were, in fact, under the old compact" — and closed with a concrete application from South Carolina's own recent judicial practice: the 1783 peace treaty's discharge of "upwards of one hundred recognizances" at the Ninety-Six court. Hon. John Rutledge, also a Federal Convention delegate, corroborated with the same 1783 parliamentary-censure precedent he used answering Lowndes on the Treaty Clause itself (see Treaty and Appointments Clause), and Mr. Speaker (Hon. John Julius Pringle) closed the round rejecting Lowndes's instalment-law fear as resting on a mistaken premise about how the clause operates prospectively rather than retrospectively — the same prospective-only reading Maclaine and Davie would give North Carolina's convention six months later over paper money (above): "As for the danger of repealing the instalment law, the gentleman has forgot that one article ordians [sic] that there shall be no retrospective law."

key-insight

South Carolina's Lowndes-Pinckney exchange is the wiki's earliest ratifying-era floor debate on this clause by several months, and its only one to combine a verbatim reading of the clause with law-of-nations authority (Vattel, Burlamaqui) rather than domestic constitutional argument alone. Where Mason's Virginia objection and North Carolina's Bloodworth/Caldwell exchange (both above) both treat the clause as a domestic sovereignty or bill-of-rights problem, Lowndes and Pinckney fight the same clause almost entirely on the ground of whether treaties bind a republic's own citizens the same way they bind a monarch's subjects — a register no other state convention on this page repeats.

"Sydney" (Robert Yates) returns to "in pursuance thereof," a year after satisfying himself on "constitutionally made"

This page already records Robert Yates's Confederation-era exchange over the 1783 peace treaty: on 20 March 1787, Yates objected that Congress's resolution declaring a treaty "the law of the land" went too far unless "clothed with legal sanction," and was answered, and satisfied, the next day by the qualifying phrase "constitutionally made." Fourteen months later, writing as "Sydney" in the New York Daily Patriotic Register (13-14 June 1788; the collection's own headnote identifies the pseudonym as Yates — see Robert Yates), Yates returned to the identical construction question the ratified Supremacy Clause's own "in Pursuance thereof" language raises, and this time rejected the restrictive reading he had accepted in 1787:

"Those who are full of faith, suppose that the words "in pursuance thereof" are restrictive, but if they reflect a moment and take into consideration the comprehensive expressions of the instrument, they will find that their restrictive construction is unavailing, and this is evidenced by 1st art., 8th sect., where this government has a power "to lay and collect all taxes, duties, imposts and excises, to pay the debts, and provide for the common defense and general welfare of the United States," and also "to make all laws which shall be necessary and proper for carrying into execution the foregoing powers vested by this constitution in the government of the United States, or in any department or office thereof."" — "Sydney" (Robert Yates), The Anti-Federalist Papers No. 45, New York Daily Patriotic Register, 13-14 June 1788

key-insight

The 1787 exchange and the 1788 "Sydney" essay put the same man on opposite sides of a structurally identical question a year apart, but the questions are not quite identical: in 1787, Yates was satisfied that "constitutionally made" adequately qualified a single treaty already agreed to under the Confederation's own Article 9 treaty power. In 1788, writing against the new Constitution, he argues the ratified clause's parallel "in Pursuance thereof" qualifier does no real limiting work once read against the Necessary and Proper and General Welfare language already carried on Necessary and Proper Clause — because that combination, on his reading, makes it Congress's own discretion, not any external textual limit, that decides what counts as "in pursuance." Whether this is a change of mind or a distinction between a specific treaty and an open-ended domestic lawmaking power is not resolved by anything else on this page.

Doctrinal evolution

The clause's first major test came in Ware v. Hylton, 3 Dall. 199 (1796), where the Court held that Article IV of the 1783 Treaty of Paris overrode a Virginia statute purporting to extinguish British debts, and that state judges were bound to treat contrary state constitutions and laws as void. Justice Chase's opinion applies the founding-era reasoning of Federalist Nos. 33 and 44 directly: a treaty "cannot be the supreme law of the land ... if any act of a state legislature can stand in its way."

The clause's most consequential judicial extensions came from Chief Justice Marshall: McCulloch v. Maryland, 17 U.S. 316 (1819), held Maryland could not tax the Bank of the United States, since "the power to tax involves the power to destroy" a validly constituted federal instrumentality; Cohens v. Virginia, 19 U.S. 264 (1821), confirmed Supreme Court appellate jurisdiction over state-court judgments touching federal law, over Virginia's objection that this offended state sovereignty; Gibbons v. Ogden, 22 U.S. 1 (1824), voided a New York steamboat monopoly as preempted by a federal coasting license; and American Insurance Co. v. Canter, 26 U.S. 511 (1828), applied federal supremacy to territorial governance.

Federal supremacy was also contested outside the courts. The 1798 Kentucky and Virginia Resolutions, responding to the Alien and Sedition Acts, advanced a compact theory under which states retained authority to judge federal overreach — the doctrinal ancestor of later interposition and nullification claims. That theory did not prevail in the courts; Ware, McCulloch, and Cohens all proceed on the premise that the Constitution's supremacy is enforced by federal courts against state actors, not negotiated between sovereigns of equal final authority.

gap

The extract for this ingest does not reach the Founders' Constitution documents on United States v. Robins, United States v. Schooner Peggy, or the Andrew Jackson bank-veto message (Documents 25, 27, 41) — flagged for a future pass rather than summarized from memory.

Story's Commentaries draw Judicial review directly out of this clause's supremacy, immediately after discussing it: "From this supremacy of the constitution and laws and treaties of the United States, within their constitutional scope, arises the duty of courts of justice to declare any unconstitutional law passed by congress or by a state legislature void" (§ 1836) — while limiting federal judicial review of state statutes to conflicts with the federal Constitution, not a state statute's conflict with its own state constitution. See Judicial review for the fuller Story treatment and its Calder v. Bull and Satterlee v. Matthewson citations.

Modern doctrine: federal preemption

Since the mid-twentieth century the Supreme Court has channeled most Supremacy Clause litigation into the vocabulary of "federal preemption" — express versus implied preemption, field versus conflict preemption, and (in implied-preemption cases) a presumption against reading federal law to displace the states' historic police powers absent a clear and manifest congressional purpose. The doctrine passed through a dual-federalism era of near-automatic field preemption (1870s-1930s), a New Deal-era course correction toward a presumption against preemption, and a modern framework that treats preemption chiefly as a question of statutory construction. See Federal Preemption for the full doctrinal history and case law (Rice v. Santa Fe Elevator Corp., Gade v. National Solid Wastes Management Ass'n, Wyeth v. Levine, Puerto Rico v. Franklin California Tax-Free Trust, Murphy v. NCAA).

Because the basic principle of federal supremacy is now well-settled, the Court has described the Supremacy Clause itself as a "rule of decision" for resolving conflicts between valid federal and state law rather than an independent source of federal power — Murphy v. NCAA, 138 S. Ct. 1461, 1479 (2018) — so contemporary federalism disputes are typically fought on the terrain of the Commerce Clause, the Spending Clause, and the Fourteenth Amendment instead.