The Senate has 100 members with each state having two senators, elected at-large to six-year terms; one-third of Senate seats are up for election every two years. The District of Columbia and the five major U.S. territories do not have senators. The president serves a four-year term and may be elected to the office no more than twice. The president is not elected by direct vote, but by an indirect electoral college system in which the determining votes are apportioned to the states and the District of Columbia. The Supreme Court, led by the chief justice of the United States, has nine members, who serve for life.