The landmark Supreme Court decision Marbury v. Madison established which principle?

• A. The right to free speech
• B. Judicial Review
• C. Federalism
• D. Separation of church and state

Answer: (B)

The main idea here is judicial review—the power of courts to examine laws and government actions and strike down those that violate the Constitution. Marbury v. Madison established that principle by holding that it is the judiciary’s duty to interpret the Constitution and to nullify any act of Congress or the executive branch that conflicts with it. This creates a crucial check and balance, ensuring that the other branches cannot exceed their constitutional authority. The decision also solidified that the Constitution is the supreme law of the land, and the courts are the ultimate interpreters of its meaning. In this context, the other ideas—protecting free speech, distributing power between national and state governments, or keeping religion separate from government—are important topics, but they do not describe who can declare laws unconstitutional.