The Supremacy Clause of the U.S. Constitution establishes that federal law takes precedence over state law, which means state officials generally cannot prosecute federal agents for actions taken in the course of their federal duties.
October 24, 2025
high
constitutional
The constitutional doctrine of federal supremacy limits state authority to interfere with federal officers performing official functions.
The U.S. Supreme Court in McCulloch v. Maryland (1819) held that a state could not impose a tax on a federal institution because such a tax would violate the Constitution's Supremacy Clause.
March 06, 1819
high
legal
Landmark Supreme Court decision interpreting the relationship between federal and state authority.
The U.S. Constitution's Supremacy Clause establishes that federal law takes precedence over conflicting state law.
September 17, 1787
high
legal
Constitutional principle that allocates authority between federal and state law.
The Supremacy Clause of the U.S. Constitution can be invoked as a legal basis to challenge state criminal charges by arguing that federal law or federal official duties preempt state law.
high
legal
Use of Supremacy Clause in legal defenses against state prosecution
The Supremacy Clause of the United States Constitution establishes that federal law is the supreme law of the land and takes precedence over conflicting state law.
high
constitutional
Defines hierarchical relationship between federal and state law.