If there was an award in politics for self-inflicted political damage, Tennessee Sen. Bob Corker would be a shoo-in. The senator gratuitously napalmed his political career by slamming President Trump in scathing terms, and now wants to keep his job in the Senate even after retiring and losing support from much of his political base.

Corker’s sudden change of heart is infuriating Republican officials tasked with maintaining the GOP’s Senate majority, who view his indecision as a distracting sideshow in a must-win race. He would have been a clear favorite for reelection, but his retirement and Trump bashing opened up a promising opportunity for ambitious successors. Rep. Marsha Blackburn, the leading contender to succeed him, raised a whopping $2 million in the last quarter and consolidated support from disparate wings of the Republican party.

“It’s Bob drafting Bob. It’s ridiculous. It’s a solution in search of problem. Marsha is the best candidate anywhere in the country,” said one senior Republican Senate strategist unaffiliated with the race. “She’s done more from a campaign point of view than any other Senate race.”