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Technology

The Doctrine of Preemption in Federal-State Conflicts

Quick fact

Under the Supremacy Clause of the U.S. Constitution, federal law is the 'supreme Law of the Land,' so when a valid federal law conflicts with a state law, the state law is invalidated—even if it was passed by a democratically elected state legislature and supported by state voters.

Why this is interesting

What happens when a state law and a federal law collide—when complying with one means breaking the other? The answer lies in a powerful doctrine that decides the winner in these legal showdowns.