As in the House of Representatives, political parties and a committee system dominate procedure and organization. Each party elects a leader, usually a senator who is influential in his or her own right, to coordinate the activities of the Senate. The leader of the largest party is known as the majority leader, while the leader of the opposition is known as the minority leader. Senate leaders also play an important role in appointing members of their party to Senate committees that review and process legislation and exercise general oversight of government agencies and departments. The Vice President of the United States is the President of the Senate, but can only vote in cases of ties. In the absence of the vice president, the Senate is presided over by the president pro tempore, usually the member of the majority who has held the longest tenure.
Sixteen standing committees are grouped mainly around major policy areas, each with a staff, budget and various subcommittees. Each committee is chaired by a member of the majority party. Important standing committees include Appropriations, Finance, Government Operations, Foreign Relations, and the Judiciary. Thousands of bills are referred to committees during each session of Congress, although the committees consider only a small fraction of these bills. Markup sessions, which can be open or closed, consider the final language of the law. Committees hold hearings and call witnesses to testify on legislation that is assigned to them. Select and special committees are also created to conduct research or to conduct investigations and report to the Senate; these committees deal with issues of aging, ethics, Indian affairs, and intelligence.
The Senate’s smaller membership allows for more extended debate than is common in the House. To check cloture – endless debate that impedes legislative action – three-fifths of the members (60 senators) must vote for cloture. (In 2013, the Senate’s rule on cloture was changed to allow for cloture by majority vote for all presidential nominations except those to the Supreme Court, and in 2017 the rule was similarly interpreted for Supreme Court nominations.) If the legislation under discussion were to change the Senate’s standing rules, a closure could be triggered by only a two-thirds vote of those present. There is a less elaborate structure of party control in the Senate; the position taken by influential senators may be more important than the position (if any) taken by a party.
Constitutional provisions for qualifications of Senate members specify a minimum age of 30 years, nine years of U.S. citizenship, and residency in the state from which elected.
