The U.S. Constitution, as established by the Supremacy Clause in Article VI, Clause 2, takes precedence over state laws and state constitutions.

This means that when there is a conflict between federal law (including the Constitution) and state law, the federal law will supersede the state law.

The Supremacy Clause explicitly states that the Constitution, federal laws made pursuant to it, and treaties are the "supreme Law of the Land".

State courts are bound by this principle, and state constitutions are subordinate to federal law when there is a conflict.

However, federal laws must still operate within the constitutional limits of the powers granted to the federal government, such as those enumerated in the Constitution and not prohibited by amendments like the Tenth Amendment.