Marbury v Madison established which principle?

• A. Separation of powers
• B. Judicial review
• C. Popular sovereignty
• D. Due process

Answer: (B)

Judicial review is the power of courts to interpret the Constitution and strike down laws or government actions that conflict with it. In Marbury v Madison, the Supreme Court used this power to establish that principle as a binding rule. The case involved William Marbury seeking a writ of mandamus to compel James Madison to deliver his commission. The Court ruled that while Marbury was entitled to his commission, the portion of the Judiciary Act of 1789 that would have granted the Court original authority to issue such writs went beyond what the Constitution allowed. By declaring that portion unconstitutional, the Court affirmed that the Constitution is the supreme law and that the judiciary has the duty to interpret and enforce it. This is why the decision is about judicial review—the authority of the courts to review and invalidate laws or actions that contradict the Constitution. While separation of powers explains the general framework of checks and balances, and due process and popular sovereignty cover other constitutional ideas, Marbury’s main contribution is establishing the judiciary’s power to review and override unconstitutional actions.