In the law of the United States, federal preemption is the invalidation of a U.S. state law that conflicts with federal law.

What is an example of preemption?

Preemption applies regardless of whether the conflicting laws come from legislatures, courts, administrative agencies, or constitutions. For example, the Voting Rights Act, an act of Congress, preempts state constitutions, and FDA regulations may preempt state court judgments in cases involving prescription drugs.

What does preemption mean in government?

Preemption occurs when, by legislative or regulatory action, a “higher” level of government (state or federal) eliminates or reduces the authority of a “lower” level over a given issue. ... Similarly, states almost always have broad authority to preempt local laws.