Republican politics in Georgia just went nuclear.

Former senator David Perdue announced on Monday that he would challenge incumbent Gov. Brian Kemp in next May’s primary. This battle royal, fueled by former president Donald Trump’s pique and Perdue’s ambition, is terrible for the health of the Peach State’s GOP. It’s imperative that Republicans — and independents who fear Trump’s designs on democracy — back Kemp to the hilt.

Perdue’s announcement is a bizarre mix of fantasy and falsehood. He blames Kemp for his own defeat in last January’s runoff election because Kemp refused to overturn the results of the November 2020 election at Trump’s behest. Perdue failed to win a majority of the vote that fall, thereby forcing the runoff, but somehow that failure isn’t his fault.

Perdue also did not make Kemp’s behavior a focus during his tense runoff battle, even though Trump made it the focus of his remarks at an election eve rally supposedly for Perdue’s benefit. Indeed, at the time, Perdue was trying to dance between maintaining Trump’s support and avoiding an embrace that had already cost him dearly in Atlanta’s suburbs.

That failure in the suburbs is why Perdue lost, and it is because of one man only: Donald Trump. Perdue carried the key suburban counties of Cobb and Gwinnett by 13 and 10 points, respectively, in his comfortable seven-point statewide win in 2014. This echoed Mitt Romney’s strong performance in those counties in the 2012 presidential election by nearly identical margins. Trump, however, so alienated well-to-do suburbanites that he lost both counties to Hillary Clinton in 2016 even as he carried Georgia by a smaller-than-expected five points. Kemp, who had been endorsed by Trump, did even worse there in 2018, losing both counties by double digits.

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The anti-Trump suburban wave became a tsunami in 2020 that drowned Perdue. Trump was annihilated in Cobb and Gwinnett, losing them by 14 and 18 points, respectively, one of the largest swings away from the GOP in the country. Perdue lost them by 10 and 16 points in the November election and by 12 and 20 points in the runoff.

Perdue’s ambition has now led him to embrace the man who cost him his Senate seat, apparently deciding that it’s better to switch than fight. Perdue, in his announcement video, said Kemp’s refusal to bow to Trump’s pressure is why Republicans lost the Senate runoff. Perdue also took aim at Republican Secretary of State Brad Raffensperger, who also refused to bow to Trump’s demands and certified the November election results. Trump is expected to reward Perdue for his fealty with an endorsement soon, thereby making clear that Perdue is his vassal.

Republicans should back Kemp in this unnecessary race. Kemp has been a standard conservative in office, signing income tax cuts in 2019 and 2021. He signed a bill banning local efforts to defund the police and is a staunch Second Amendment supporter. Kemp also signed a bill in 2019 that would ban abortions after a fetal heartbeat is detected. Enforcement of that bill has been blocked since its passage because it conflicts with Roe v. Wade, but would go into effect should the Supreme Court overturn that decision, as many now expect. Perdue’s announcement didn’t mention one instance of Kemp not supporting the conservative agenda. That’s probably because he can’t find any.

Independents concerned about our democracy should also back Kemp in the Republican primary. Kemp and Raffensperger are the national poster children for Republican refusal to kowtow to Trump’s unconscionable demands. If they lose their bids for reelection, Republican officeholders across the country will reassess whether they could withstand similar onslaughts.

Georgia does not have partisan voter registration, so any voter can vote in any party’s primary. Liberal independents can even vote for Kemp in the primary and his likely Democratic opponent, progressive icon Stacey Abrams, in the general election. Similar crossover primary voting saved former senator Thad Cochran (R-Miss.) from an ultraconservative primary challenge in 2014; Romney-Biden suburban Republicans should do the same to back Kemp if they are serious about protecting democracy from Trump.

Perdue’s challenge is serious. A poll commissioned in August by Trump’s Save America PAC found that Perdue would lead Kemp if he had Trump’s endorsement, although even in that scenario Perdue would be well short of the majority needed to avoid a runoff. Kemp, to his credit, is going nowhere and is planning to wage a no-holds-barred campaign. A Republican strategist quipped that “Sherman left more standing than this primary will,” and he’s probably right.

Georgia has now become ground zero for the battle over Trump’s influence within the Republican Party. For Republicans who want to move on from Trump, and for former Republicans who want their party back, there’s only option: make sure Brian Kemp wins.