Incumbent Republican senator Bob Corker opted to retire instead of running for a third term.

Republican U.S. representative Marsha Blackburn won the open seat, defeating former Democratic governor Phil Bredesen.

The primaries took place on August 2, 2018, with Blackburn and Bredesen winning their respective party nominations.

However, Corker said he would vote for Blackburn and donate to her campaign, and questioned whether Bredesen would be able to win a Senate seat in a red state like Tennessee.

The endorsement was notable given that Swift had previously been publicly apolitical, but spoke out because Blackburn's voting record in Congress "appalled" and "terrified" her.

Polls showed the race as close until the confirmation hearings for Supreme Court Justice Brett Kavanaugh started, which many Tennesseans believed the Democratic Party handled poorly.