Since the impeachment process requires a trial by the United States Senate, and since the constitutional provision concerning federal judges ' tenure can not be changed without the ratifications of three - fourths of the states, federal judges have perhaps the best job security available in the United States. Moreover, the Constitution forbids Congress to diminish a federal judge 's salary. Twentieth - century experience suggests that Congress is generally unwilling to take time out of its busy schedule to impeach and try a federal judge until, after criminal conviction, he or she is already in prison and still drawing a salary, which can not otherwise be taken away (see Nixon v. United States, a key Supreme Court case about Congress 's discretion in impeaching and trying federal judges).
why can salaries for federal judges not be reduced by congress
the Constitution forbids Congress to diminish a federal judge 's salary