Clarence William "Bill" Nelson II (born September 29, 1942) is an American politician and member of the Democratic Party who serves as the senior United States Senator from Florida, in office since 2001. Nelson began his career in the Florida House of Representatives, where he served from 1973 to 1979. He then served in the United States House of Representatives from 1979 to 1991 and in January 1986, Nelson became the second sitting member of the United States Congress to fly in space.