A senator is a member of the United States Senate, which is the upper chamber of the United States Congress. The Senate, together with the House of Representatives, makes up the federal bicameral legislature of the United States. The Senate is composed of 100 senators, with each state electing two senators. Senators are elected to serve six-year terms, and every two years, the members of one class, approximately one-third of the senators, face election or reelection. The Constitution sets three qualifications for service in the U.S. Senate: age (at least thirty years of age), U.S. citizenship (at least nine years), and residency in the state a senator represents at the time of election. Senators have several constitutional powers, including proposing legislation, drafting or amending bills, filibustering, oversight of the federal budget, and approving or rejecting presidential appointees for agencies. The Senate also has the power to convict an executive or judicial official with a two-thirds vote in an impeachment trial. The Vice President of the United States serves as President of the Senate and may cast the decisive vote in the event of a tie in the Senate.