The Supremacy Clause says that the U.S. Constitution and valid federal laws are higher than and override conflicting state laws.

Core wording

The Supremacy Clause is in Article VI, Clause 2 of the U.S. Constitution. It states that:

“This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.”

In plain terms, the Constitution, federal statutes made under it, and U.S. treaties are the supreme law, and state judges must follow them even if state constitutions or laws say something different.

What it means in practice

  • If a state law conflicts with a valid federal law, the federal law wins and the state rule is invalid to the extent of the conflict.
  • State judges are required to apply federal law over contrary state rules in their decisions.
  • The clause underpins “federal preemption,” the idea that Congress can effectively displace state regulation in certain areas when it legislates within its constitutional powers.

A simple illustration: if Congress passes a transportation safety rule within its constitutional authority, and a state passes a contradictory safety rule on the same topic, courts will treat the federal rule as controlling and disregard the conflicting part of the state rule.

Why it was included

The clause was designed to solve a problem from the Articles of Confederation era, when states sometimes ignored national decisions. By expressly making national law “the supreme Law of the Land,” the Constitution ensures a unified legal baseline across all states while still allowing them to legislate in areas not overridden by federal law.

Information gathered from public forums or data available on the internet and portrayed here.