courts. The Federalists complained that this violated the tenure of judges, a right guaranteed by the Constitution. In a related case, Marbury v. Madison (1803), the Supreme Court ruled that the Judiciary Act itself had been unconstitutional. As Chief Justice John Marshall intended, the Republicans considered the ruling a victory and overlooked the fact that the Court had judged the constitutionality of an act of Congress (judicial review). After their "victory" in the Marbury case, Republicans pressed their attack on the court system. One judge, certifiably insane, was impeached and removed from office. Some Republicans now began to fear a complete destruction of an independent judiciary, an important element in the system of checks and balances. When Jefferson sought impeachment of a judge who, though partisan, had committed no crime, Republican unity disappeared. The trial itself made clear that impeachment could be voted only on narrow political grounds. A Republican Senate refused to convict, and the attack against the judicial system ended.