What does the supremacy clause say? What does this mean?
The Supremacy Clause, found in Article VI, Clause 2 of the United States Constitution, establishes that the Constitution, federal laws, and treaties made under the authority of the United States are the supreme law of the land. It states: "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."
This clause means that any state or local laws that conflict with the Constitution, federal laws, or treaties are invalid. It ensures that the federal government has the ultimate authority and supremacy over state governments in cases where there is a conflict of laws. Consequently, if a federal law and a state law contradict each other, the federal law prevails and must be followed.