Judicial Review

Explanation

Judicial review allows courts to act as a check on the legislature and executive by invalidating laws or acts that violate the constitution. In the United States, the Supreme Court has exercised this power since Marbury v. Madison (1803), though it is not explicitly granted in the Constitution. Other countries use dedicated constitutional courts (Germany's Bundesverfassungsgericht, France's Conseil Constitutionnel) for this function. The UK traditionally lacks constitutional judicial review because of parliamentary sovereignty, though the Supreme Court has limited review powers. Judicial review is a core mechanism of the separation of powers and constrains democratic majorities from violating fundamental rights.