What is the effect of the Supremacy Clause on conflicting laws?

• A. The Constitution and federal laws are the supreme law of the land; federal law preempts conflicting state laws.
• B. State constitutions are supreme within their borders.
• C. The clause applies only to treaties.
• D. Federal law preempts state laws only when Congress explicitly acts.

Answer: (A)

The Supremacy Clause says that the Constitution, federal laws, and treaties are the supreme law of the land. When a state law conflicts with that federal law, the federal law preempts the state law to the extent of the conflict. In practice, this means the state rule is invalid where it clashes with federal law, ensuring uniform application across states.

This helps explain why the federal framework takes priority: state constitutions aren’t supreme over the federal Constitution, and the clause covers more than treaties, not just treaties. Preemption can occur even without an explicit statement from Congress, through implied preemption when a valid federal purpose is at stake or the federal scheme occupies the field.