What is judicial review, and where does it come from?

Judicial review is the authority of courts to examine legislative and executive actions for constitutionality and to refuse to give effect to those that conflict with the Constitution. It is the mechanism by which constitutional limits become enforceable rather than aspirational. Notably, the Constitution does not grant this power explicitly. It was asserted by Chief Justice John Marshall in Marbury v. Madison in 1803, reasoning that the Constitution is superior law, that courts must say what the law is when deciding cases, and that a law repugnant to the Constitution therefore cannot be applied.

The case itself is a study in strategic decision-making. Marshall found that Marbury was entitled to his commission and that the law giving the Court jurisdiction to order it was itself unconstitutional, which meant the Court could not grant the relief. The practical effect was that the Jefferson administration won the immediate dispute and had nothing to defy, while the Court established a far more significant power that no one was positioned to contest. The Court did not strike down another federal statute for over fifty years, and that case was Dred Scott.

Two ongoing tensions follow. Judicial review gives unelected judges with life tenure the power to void the acts of elected legislatures, which is the countermajoritarian difficulty that constitutional theory has argued about ever since, producing competing philosophies of interpretation from originalism to living constitutionalism. And the Court has no enforcement mechanism of its own, relying on the other branches to comply, which has held remarkably well but is a norm rather than a guarantee. Most constitutional democracies established since have adopted some form of judicial review, frequently through a dedicated constitutional court rather than the ordinary court system.