Thomas Stewart "Tom" Udall (born May 18, 1948) is an American politician. He was the United States Senator from New Mexico from 2009 to 2021 and a member of the Democratic Party. First elected to the Senate in 2008, he represented as a member of the United States House of Representatives from 1999 to 2009. He was the Attorney General of New Mexico from 1991 to 1999.