Answer:
Supremacy clause.
Step-by-step explanation:
Supremacy Clause
This is known as the highest form of law in the U.S. legal system. Its mandates is that all state judges must follow federal law in time of conflict between federal law and either the state constitution or state law of any state. It is known also as a clause of the u.s construction that states that the u.s constitution and federal treaties,laws, and regulations are the supreme law of the land.