Glossary on the Republic

Judicial review

Courts

The Supreme Court's single greatest power is not written anywhere in the Constitution. The Court simply claimed it, in 1803, and never let go.

Judicial review is the power of courts to examine a law or government act, measure it against the Constitution, and refuse to enforce it if it conflicts. It is what makes the Constitution enforceable rather than just inspiring words on parchment.

Here is the surprise: the Constitution never explicitly grants this power. The framers debated it, and Hamilton argued for it in Federalist No. 78, calling the judiciary the least dangerous branch with neither force nor will, only judgment. But the text itself is silent.

The power was seized, not given. In Marbury v. Madison in 1803, Chief Justice John Marshall reasoned that since the Constitution is the supreme law, any ordinary law that conflicts with it must fall, and that it is the courts' job to say so. The logic was so compelling it stuck.

For decades the Court used the power sparingly, but it grew into the engine of constitutional law. Every time a court strikes down a statute, blocks an order, or protects a right against the government, it is exercising the authority Marshall claimed out of thin air.

Origin

Established by Marbury v. Madison, 1803; argued earlier in Federalist No. 78.

Why it matters

Judicial review is why a court can tell the most powerful government on earth that it has broken its own founding rules, and have that ruling hold. It rests not on an explicit grant of power but on an idea: that the Constitution is law, real law, and someone must have the final say on what it means.