Which doctrine holds that federal law takes precedence over state law when there is a conflict?

• A. Dual federalism
• B. National supremacy
• C. Nullification
• D. Cooperative federalism

Answer: (B)

The main idea here is that federal law overrides state law when there is a conflict, a principle grounded in the Supremacy Clause. The Supremacy Clause, in the Constitution, declares that federal laws made under the Constitution are the supreme law of the land. When a state law clashes with that federal law, the federal provision prevails through the idea of preemption. This is commonly described as national supremacy.

This isn’t about two areas operating independently, as in dual federalism, nor about states claiming the right to ignore federal laws, as in nullification. It also isn’t about the cooperative blending of powers, which is a later, more collaborative view of federal-state relations. A simple way to see it is: if federal law says something must be done a certain way, a conflicting state rule cannot stand.