On December 17, 2018, U.S. Sen. Lamar Alexander (R-TN) announced that he would not seek re-election to his seat in 2020. He was first elected to the Senate in 2002 and was re-elected in 2008 and 2014. Alexander was previously a two-term governor of Tennessee and served for two years as the U.S. Secretary of Education under George H. W. Bush.
Both U.S. Senators from Tennessee have been Republicans since 1995. The last time a Democrat won a Senate election in the state was in 1990 when then-Senator and future Vice President Al Gore won re-election to his second term.
Democrats held both U.S. Senate seats in the state from 1913 through 1994, with two exceptions. Former Senate Majority Leader Howard Baker (R) served three terms from 1967 until 1985, and William Brock (R) represented the state for one term in the 1970s.