The U.S. Senate is comprised of two senators from each state elected by the citizens of their respective states. The Vice President of the United States leads the Senate. Underneath him, the majority party elects a group of majority leaders. The other party elects minority leaders. These individuals serve as spokespeople for their parties on the Senate floor.
Members of the Senate are elected to six-year terms by popular vote. However, the terms are rolling, and in any given year, about one-third of the Senate is up for re-election. The Senate is subdivided into committees and sub-committees that funnel and filter the various legislative duties of Congress. Majority and minority leaders of the Senate are supported by Whips, who are also elected to their positions. The primary duty of Whips is to make sure that a party remains a cohesive unit and that everyone casts votes when crucial bills come to the floor. Whips, Majority Leaders and Minority Leaders are all elected by a simple majority of their party. According to the U.S. Constitution, the Vice President of the United States is the head of the Senate. The Senate also has a President Pro-Tempore, who presides over the Senate in the absence of the vice president.