The Supremacy Clause

§6.2.1 Types of Preemption

There are three circumstances under which federal law preempts state law. The first involves express preemption while the latter two deal with implied preemption. First, when Congress expressly describes the extent to which a federal enactment preempts state law, there is express preemption and any state law contrary to that express design will be preempted. National Meat Association v. Harris, 132 S. Ct. 965 (2012); Riegel v. Medtronic, Inc., 552 U.S. 312, 321-325 (2008). Note, however, that “when the text of a pre-emption clause is susceptible of more than one plausible reading, courts ordinarily ‘accept the reading that disfavors pre-emption.’” Altria Group, Inc. v. Good, 555 U.S. 70, 77 (2008) (quoting Bates v. Dow Agrosciences LLC, 544 U.S. 431, 449 (2005)). Second, when state law clashes with federal law by imposing inconsistent obligations on affected parties or by interfering with the objectives of a federal scheme, the state law is subject to conflict preemption under which the conflicting provisions of state law will be struck. Finally, if a state law operates within a field of law that Congress intends the federal government to occupy exclusively, the state law will be preempted under a theory of field preemption. As we will see, these types of preemption may sometimes overlap.

Whether federal law preempts state law in any particular case depends completely on the intent of Congress. See Wyeth v. Levine, 555 U.S. 555, 565 (2009) (“purpose of Congress is the ultimate touchstone in every pre-emption case”). When the intent is express, the question of preemption is greatly simplified. Suppose, for example, that a federal statute prohibited states from regulating the “price, route, or service of any motor carrier with respect to the transportation of property.” A state law that purported to impose route restrictions on such services would be expressly preempted by the text of the federal statute. If the same federal law, however, contained a saving clause providing that its preemptive scope “shall not restrict the safety regulatory authority of a State with respect to motor vehicles,” a state law that imposed route restrictions based on genuine safety considerations would not be preempted. See Columbus v. Ours Garage and Wrecker Service, 536 U.S. 424 (2002) (construing the preemptive reach of a similar statutory scheme); see also Egelhoff v. Egelhoff, 532 U.S. 141 (2001) (ERISA expressly preempts state law pertaining to the designation of beneficiaries under a covered life insurance policy and pension plan). When a federal statute’s express preemption provision contains a saving clause, there may still be an issue as to whether a particular state law falls within the scope of that clause. See, e.g., Chamber of Commerce v. Whiting, 131 S. Ct. 1968 (2011) (Court dividing 5-3 on question of whether challenged Arizona statute fell within saving clause of a federal statute’s preemption provision).

In cases not involving express preemption, however, the intent of Congress must be inferred from the circumstances. In cases of conflict preemption, the intent to preempt is inferred from the direct clash between federal and state law. The inference of intent may be somewhat more difficult to establish in potential cases of implied field preemption; the techniques for doing so will be examined below. The question of implied preemption may arise even in cases that fall within the saving clause of an express preemption provision. In other words, the fact that Congress chose not to expressly preempt a particular type of state law does not by itself warrant a conclusion that Congress also meant to shield, from implied preemption, those state laws that are disruptive of the federal scheme in question. Geier v. American Honda Motor Co., Inc., 529 U.S. 861, 869 (2000) (“We … conclude that the saving clause (like the express preemption provision) does not bar the ordinary working of conflict pre-emption principles”); see also Chamber of Commerce v. Whiting, supra, 131 S. Ct. at 1981-1985 (after finding that state law fell within saving clause of a federal statute’s express preemption provision, Court went on to consider whether there was implied preemption).