U.S. Rep. Marsha Blackburn announced her campaign for U.S. Sen. Bob Corker's seat on Thursday in a video that slams the "totally dysfunctional" Senate and Republicans in particular for their failure to repeal the Affordable Care Act.
Blackburn also touts her support for gun rights, opposition to abortion rights and calls for more limits on government spending in the video.
"I know the left calls me a wingnut or a knuckle-dragging conservative," she said. "And you know what? I say that's all right. Bring it on."
Blackburn's entry followed a decision earlier in the day by term-limited Gov. Bill Haslam to sit out the race, despite entreaties from Corker, Senate Majority Leader Mitch McConnell of Kentucky and Tennessee's senior senator, Lamar Alexander.
"While I have loved being a mayor and a governor, I don't feel the same call to run for Senate at this point," said Haslam. He said the hyper-partisanship that surrounds Congress was a factor in his decision.
"The result is a Washington that is broken because neither side is willing to say: 'I get it, half of the country feels very differently — what can we work out to make it better?'" the governor said.
Haslam's popularity in the state and his vast personal wealth would have made him a strong candidate, despite lingering anger among some Republicans over his call to Donald Trump to abandon his presidential nomination last year following the release of a videotape in which Trump boasted about groping women.
Corker, who announced last week that he wouldn't seek a third term, also publicly criticized the Republican president, for his repose to a deadly white nationalist rally in Virginia. Corker questioned whether Trump had the "competence" or "stability" to succeed in office.
Blackburn has made her own critical comments about "inappropriate and pointless tweets" from the president, but was quick to embrace the Trump agenda in her campaign announcement video.
"I believe in President Trump's immigration ban, and I'll fight with him every step of the way to build that wall," she said. "I stand when the president walks in room, and yes, I stand when I hear the Star Spangled Banner."
Former U.S. Rep. Stephen Fincher is another potential Republican Senate candidate, and is expected to make a decision in the coming days. Haslam hasn't said whether he'll endorse a Republican in the race.
Blackburn's decision opens a third Republican House seat in the Tennessee delegation next year, following Rep. John J. "Jimmy" Duncan Jr.'s plans to retire and Rep. Diane Black's decision to run for governor.
State Sen. Mark Green, who withdrew as Trump's nominee for Army secretary earlier this year amid criticism of his comments about gay and transgender people, said he will run for Blackburn's House seat.
This story has been updated.