Definitions for "Supremacy clause"
Article IV, Section 2 of the U.S. Constitution states that in cases of conflict between federal and state laws that federal law is superior to and overrides state law.
This clause, contained in Article VI of the U.S. Constitution, establishes that the Constitution, all laws made pursuant to the Constitution, and all treaties made under the authority of the United States are the "supreme law of the Land." This has been interpreted to mean that any law made by the federal government pursuant to authority granted in the Constitution trumps any conflicting provision of a state constitution or state or local law.
Article VI, Section 2, of the Constitution, which states that the Constitution, laws passed by Congress, and treaties of the United States "shall be the supreme law of the land," binding on the states.