Article III: The Judicial Branch

Article III is the shortest of the three branch articles. Section 1 vests the judicial power in one Supreme Court and in such inferior courts as Congress may establish, leaving the size of the Court and the entire lower court system to Congress. It also gives judges tenure during good behavior and forbids reducing their pay while in office, the twin guarantees of judicial independence.

Section 2 lists the cases and controversies the federal judicial power can reach, including those arising under the Constitution, federal laws, and treaties, cases affecting ambassadors, admiralty cases, and controversies between states or citizens of different states. The Eleventh Amendment, ratified in 1795, withdrew suits against a state by citizens of another state. The Supreme Court has original jurisdiction over cases involving states and ambassadors and appellate jurisdiction over the rest, with such exceptions as Congress makes. Section 2 also guarantees trial by jury in federal criminal cases, in the state where the crime occurred.

Section 3 defines treason, the only crime the Constitution itself defines, as levying war against the United States or adhering to its enemies, giving them aid and comfort, and requires the testimony of two witnesses to the same overt act or a confession in open court. The framers wrote this narrow definition to prevent treason charges from being used against political opponents. Fewer than forty federal treason prosecutions have been brought in American history. Article III does not mention judicial review, which the Court established in Marbury v. Madison.