Supremacy Clause

The Supremacy Clause is the provision in Article Six, Clause 2 of the United States Constitution that establishes the United States Constitution, federal statutes, and treaties as "the supreme law of the land." It provides that these are the highest form of law in the United States legal system, and mandates that all state judges must follow federal law when a conflict arises between federal law and either a state constitution or state law of any state.

The supremacy of federal law over state law only applies if Congress is acting in pursuance of its constitutionally authorized powers.

Nullification is the legal theory that states have the right to nullify, or invalidate, federal laws which they view as being unconstitutional; or federal laws that they view as having exceeded Congresses’ constitutionally authorized powers. The Supreme Court has rejected nullification, finding that under Article III of the Constitution, the power to declare federal laws unconstitutional has been delegated to the federal courts and that states do not have the authority to nullify federal law.

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