The theory of nullification has never been legally upheld by federal courts. ... The courts have decided that under the Supremacy Clause of the Constitution, federal law is superior to state law, and that under Article III of the Constitution, the federal judiciary has the final power to interpret the Constitution.

Is nullification a good idea?

First, nullification is a legally valid power for the states to exercise. ... A refusal to nullify unconstitutional federal actions creates a corresponding lack of consent for constitutional ones. This, in turn, transforms our government from a government by consent to a government by compulsion.

Why is nullification bad?

Nullification would create a patchwork of laws, rendering national governance impossible. Nullification was a factor in the lead-up to the Civil War. The Constitution grants no authority for the states to nullify. The Civil War proved that nullification is not an option.