Who can declare a law unconstitutional?

The Supreme Court has the authority to declare a law unconstitutional due to its role in interpreting the Constitution. This power emerges from the principle of judicial review, established in the landmark case Marbury v. Madison in 1803. Judicial review allows the Supreme Court to evaluate laws passed by Congress and actions taken by the Executive Branch to ensure they comply with the Constitution. When a law is deemed unconstitutional, it is rendered invalid, maintaining the system of checks and balances among the branches of government. This essential function helps to protect individual rights and uphold the rule of law in the United States.

The President, the Senate, and the House of Representatives do not possess the power to declare laws unconstitutional; rather, their roles involve creating and enforcing laws. While the President can veto legislation and members of Congress can debate and vote on laws, only the judiciary has the responsibility to interpret their constitutionality.