The Operation of the Supremacy Clause

Clause 2. 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.


When Congress legislates pursuant to its delegated powers, conflicting state law and policy must yield.8 Although the preemptive effect of federal legislation is best known in areas governed by the Commerce Clause, the same effect is present, of course, whenever Congress legislates pursuant to one of its enumerated powers. The Supremacy Clause operates whether the authority of Congress is express or implied, and whether plenary or dependent upon state acceptance. The latter may be seen in a series of cases concerning the validity of state legislation enacted to bring the states within the various programs authorized by Congress pursuant to the Social Security Act.9 State participation in the programs is voluntary, technically speaking, and no state is compelled to enact legislation comporting with the requirements of federal law. Once a state is participating, however, any of its legislation that is contrary to federal requirements is void under the Supremacy Clause.10

At the same time, however, the Supremacy Clause is not the “source of any federal rights,”11 and the Clause “certainly does not create a cause of action.”12 As such, individual litigants cannot sue to enforce federal law through the Supremacy Clause, as such a reading of the Clause would prevent Congress from limiting enforcement of federal laws to federal actors.13 Instead, without a statutory cause of action, those wishing to seek injunctive relief against a state actor that refuses to comply with federal law must rely on the inherent equitable power of courts, a judge-made remedy that may be overridden by Congress.14

Federal Immunity Laws and State Courts.—The operation of federal immunity acts15 to preclude the use in state courts of incriminating statements and testimony given by a witness before a committee of Congress or a federal grand jury16 illustrates direct federal preemption that is not contingent on state participation in a federal program. Because Congress in pursuance of its paramount authority to provide for the national defense, as complemented by the Necessary and Proper Clause, is competent to compel testimony of persons that is needed in order to legislate, it is competent to obtain such testimony over a witness’s self-incrimination claim by immunizing him from prosecution on evidence thus revealed not only in federal courts but in state courts as well.17

Priority of National Claims Over State Claims.— Anticipating his argument in McCulloch v. Maryland,18 Chief Justice Marshall in 1805 upheld an act of 1792 asserting for the United States a priority of its claims over those of the states against a debtor in bankruptcy.19 The principle was later extended to federal enactments providing that taxes due to the United States by an insolvent shall have priority in payment over taxes he owes to a state.20 Similarly, the Federal Government was held entitled to prevail over a citizen enjoying a preference under state law as creditor of an enemy alien bank in the process of liquidation by state authorities.21 A federal law providing that when a veteran dies in a federal hospital without a will or heirs his personal property shall vest in the United States as trustee for the General Post Fund was held to operate automatically without prior agreement of the veteran with the United States for such disposition and to take precedence over a state claim founded on its escheat law.22

8 Gibbons v. Ogden, 22 U.S. (9 Wheat.) 1, 210–11 (1824). See also Cipollone v. Liggett Group, Inc., 505 U.S. 504 (1992); Morales v. TWA, 504 U.S. 374 (1992); Maryland v. Louisiana, 451 U.S. 725, 746 (1981); Jones v. Rath Packing Co., 430 U.S. 519, 525 (1977).

9 By the Social Security Act of 1935, 49 Stat. 620, 42 U.S.C. §§ 301 et seq., Congress established a series of programs operative in those states that joined the system and enacted the requisite complying legislation. Although participation is voluntary, the underlying federal tax program induces state participation. See Steward Machine Co. v. Davis, 301 U.S. 548, 585–98 (1937).

10 On the operation of federal spending programs upon state laws, see South Dakota v. Dole, 483 U.S. 203 (1987) (under highway funding programs). On the preemptive effect of federal spending laws, see Lawrence County v. Lead-Deadwood School Dist., 469 U.S. 256 (1985). An early example of states being required to conform their laws to the federal standards is King v. Smith, 392 U.S. 309 (1968). Private parties may compel state acquiescence in federal standards to which they have agreed by participation in the programs through suits under a federal civil rights law (42 U.S.C. § 1983). Maine v. Thiboutot, 448 U.S. 1 (1980). The Court has imposed some federalism constraints in this area by imposing a “clear statement” rule on Congress when it seeks to impose new conditions on states. Pennhurst State School & Hosp. v. Halderman, 451 U.S. 1, 11, 17–18 (1981).

11 See Golden State Transit Corp. v. Los Angeles, 493 U.S. 103, 107 (1989).

12 See Armstrong v. Exceptional Child Ctr., Inc., 575 U.S. ___, No. 14–15, slip op. at 3 (2015).

13 Id.

14 Id. at 5–6.

15 Immunity laws operate to compel witnesses to testify even over self-incrimination claims by giving them an equivalent immunity from prosecution.

16 Adams v. Maryland, 347 U.S. 179 (1954).

17 Ullmann v. United States, 350 U.S. 422, 434–436 (1956). See also Reina v. United States, 364 U.S. 507, 510 (1960).

18 17 U.S. (4 Wheat.) 316 (1819).

19 United States v. Fisher, 6 U.S. (2 Cr.) 358 (1805).

20 Spokane County v. United States, 279 U.S. 80, 87 (1929). A state requirement that notice of a federal tax lien be filed in conformity with state law in a state office in order to be accorded priority was held to be controlling only insofar as Congress by law had made it so. Remedies for collection of federal taxes are independent of legislative action of the states. United States v. Union Central Life Ins. Co., 368 U.S. 291 (1961). See also United States v. Buffalo Savings Bank, 371 U.S. 228 (1963) (state may not avoid priority rules of a federal tax lien by providing that the discharge of state tax liens are to be part of the expenses of a mortgage foreclosure sale); United States v. Pioneer American Ins. Co., 374 U.S. 84 (1963) (Matter of federal law whether a lien created by state law has acquired sufficient substance and has become so perfected as to defeat a later-arising or later-filed federal tax lien).

21 Brownell v. Singer, 347 U.S. 403 (1954).

22 United States v. Oregon, 366 U.S. 643 (1961).