In the years between 1917 and 1975, the two-thirds cloture rule had been invoked 24 times. Senate Development and Impact on Public Policy Before the Civil War the Senate enjoyed periods in which it appeared to dominate public policy. This was especially true in the 1830's, 1840's, and 1850's, when the country and the Senate were violently divided over the issue of slavery. After the Civil War the Senate underwent a period in which power was centralized in the hands of leading party figures, senators began serving much longer periods, seniority became the criterion for advancement to committee chairmanships, and various party committees and organizations were established. The Senate has three exclusive Constitutional powers in addition to a number of powers it shares with the House of Representatives.
Conviction requires a two-thirds vote.
In its entire history the Senate has received only 12 cases and has convicted only 4 individuals, all federal judges. Second, the Senate must confirm presidential nominations by majority vote. The nominations that receive most attention are those for cabinet positions and for the Supreme Court. Other federal judges and ambassadors also require Senate confirmation and sometimes involve controversy. The Senate usually confirms appointments, sometimes after lengthy hearings.