Task of the Supreme Court Under the Clause: Preemption

In applying the Supremacy Clause to subjects that have been regulated by Congress, the Court’s primary task is to ascertain whether a challenged state law is compatible with the policy expressed in the federal statute. When Congress legislates with regard to a subject, the extent and nature of the legal consequences of the regulation are federal questions, the answers to which are to be derived from a consideration of the language and policy of the state. If Congress expressly provides for exclusive federal dominion or if it expressly provides for concurrent federal-state jurisdiction, the Court’s task is simplified, though, of course, there may still be doubtful areas in which interpretation will be necessary6 . Where Congress is silent, however, the Court must itself decide whether the effect of the federal legislation is to oust state jurisdiction.7


For a discussion of express preemption, see supra Article I: Section 3: Clause 3. [Back to text]
Treatment of preemption principles and standards is set out under the Commerce Clause, which is the greatest source of preemptive authority. [Back to text]