Preemption Doctrine in the United States

Principle that federal laws supersede or preempt state laws in certain policy areas. The preemption doctrine is grounded in the Supremacy Clause of Article VI, which provides that all laws made in pursuance of the U.S. Constitution “shall be the supreme Law of the Land.” The doctrine holds that federal law must preempt state law if the national policy considerations are sufficiently great. The national policy interest, of course, must be compatible with the legitimate exercise of federal power. As a general practice, the Supreme Court allows states to enact regulations in the policy field where the federal government has also acted. As long as the state law is supplementary to the federal law or does not interfere with the implementation of federal law, state law is generally left undisturbed. The preemption doctrine does allow, however, that even where no conflict between federal and state law exists, state law may be nullified if Congress wholly “occupies” the policy field.

See Also

Doctrine (Judicial Effects and Policies) Federalism (Judicial Effects and Policies).

Analysis and Relevance

The Supreme Court said in Pennsylvania v. Nelson (350 U.S. 497: 1956) that invoking the preemption doctrine requires the existence of at least one of three conditions. First, the federal regulation must be so pervasive as to allow reasonable inference that no room is left for state action. Congress may explicitly state such a preemptive interest, or the courts may interpret the intent of Congress to fully occupy a policy field. Second, federal regulation must involve matters where the federal interest is so dominant as to preclude implementation of state laws in the field. Third, the administration of federal laws must be endangered by potentially conflicting state laws. The policy area involved in Nelson was the regulation of seditious activity. Specifically, the question was whether the federal Smith Act prohibited enforcement of the Pennsylvania Sedition Act, which proscribed the same conduct. On the basis of the preemption doctrine and the criteria described, the Supreme Court concluded that Pennsylvania’s statute had to give way.

Notes and References

1. Definition of Preemption Doctrine from the American Law Dictionary, 1991, California