Mary Marsha Blackburn is an American politician and businesswoman serving as the senior United States senator from Tennessee. Blackburn was first elected to the Senate in 2018. A member of the Republican Party, Blackburn was a state senator from 1999 to 2003 and represented Tennessee's 7th congressional district in the United States House of Representatives from 2003 to 2019, during which time the National Journal rated her among the House's most conservative members.