What happens when a state law contradicts a U.S. federal law?
...State laws only govern the citizens within a particular state, but federal laws apply to all U.S. citizens. When state and federal laws clash, think of the federal law as the trump card. In theory, a state law that goes against federal law is null and void, but in practice, there's a bit more of a gray area. What it really comes down to is enforcement.
If a state defies federal law, but the federal government doesn't enforce its law in that state, is federal law really the trump card?...
The Doctrine of Pre-emption and The Supremacy Clause
...The law that applies to situations where state and federal laws disagree is called the supremacy clause, which is part of article VI of the Constitution. The supremacy cause contains what's known as the doctrine of pre-emption, which says that the federal government wins in the case of conflicting legislation. Basically, if a federal and state law contradict, then when you're in the state you can follow the state law, but the fed can decide to stop you.
The operative term here, though, is "can."...
What federal law says locals have to perform the duties of federal immigration authorities?
