Supremacy Clause

The Supremacy Clause is a clause in the United States Constitution, Article VI, Clause 2. This clause asserts and establishes the Constitution, the federal laws made in pursuance of the Constitution, and treaties made by the United States with foreign nations as "the Supreme Law of the Land" (using modern capitalization). The text of Article VI, Clause 2, establishes these as the highest form of law in the American legal system, both in the Federal courts and in all of the State courts, mandating that all state judges shall uphold them, even if there are state laws or state constitutions that conflict with the powers of the Federal government.

The Supremacy Clause has been interpreted to come in effect only when the Federal Government has acted in a given field. In the case of Edgar v. Mite Corporation, 457 U.S. 624 (1982), the Supreme Court ruled that "A state statute is void to the extent that it actually conflicts with a valid Federal statute." In effect, this means that a State law will be found to violate the supremacy clause when either of the following two conditions (or both) exist:^[1]

1. Compliance with both the Federal and State laws is impossible, or
2. "...state law stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress..."

The Supreme Court further found in Crosby v. National Foreign Trade Council, 530 U.S. 363 (2000), that even when a State law is not in direct conflict with a Federal law, the State law could still be found unconstitutional under the Supremacy Clause if the "state law is an obstacle to the accomplishment and execution of Congress's full purposes and objectives."^[3] Congress need not expressly assert any preemption over State laws either, because (the Supreme Court said) Congress may implicitly assume this preemption under the Constitution.^[4]