The most vulnerable Democratic senator heading into next year’s midterm election has drawn his first challenger.
Representative Buddy Carter of Georgia, a Republican, announced his entry on Thursday into the primary race seeking to challenge Senator Jon Ossoff, just days after Gov. Brian Kemp took himself out of contention.
Georgia Republicans had been waiting for months to see whether Mr. Kemp would run for the seat. He would have instantly been seen as a front-runner and a formidable challenger to Mr. Ossoff, a first-term senator.
Mr. Carter, the first Republican to take advantage of the opening, would be a relatively mainstream option, but the field could grow crowded.
Republicans in the state have worried in particular that Representative Marjorie Taylor Greene, the polarizing Trump ally who has said she is considering running, could win a primary race by attracting the most fervent right-wing voters only to lose in the general election by turning off independents and disaffected, more centrist Republicans.
Ms. Greene said in a television interview this week that she was considering a run either for Senate or for governor in 2026, and that polling showed she could win either primary. “That’s a choice that I can make, and I’ll give it some thought,” she said.
In Mr. Carter’s announcement, posted on X, he signaled that he would try to make the contest about his support for President Trump and about the sort of cultural issues that Mr. Trump seized on in the 2024 campaign, including transgender rights.
“Georgians will have a very simple choice in 2026: do you want a MAGA warrior for you or do you want a trans warrior for they/them?” Mr. Carter wrote. “I’m with you. You can guess where Jon Ossoff is.”
Mr. Carter also bought TV time for an advertisement that will begin airing on Friday, according to the tracking firm AdImpact, which put his spending on ad buys at $1.8 million so far.
In a video he released on Thursday, Mr. Carter argued that Mr. Ossoff was out of step with Georgia voters.
“Last November, Georgia spoke. But Jon Ossoff doesn’t care,” a husky-voiced narrator says in the ad. “He fought against President Trump securing our border, and voted for men in girls’ sports. Jon Ossoff is on the wrong side.”
Mr. Ossoff, seen as a rising star in Democratic politics, unseated Senator David Perdue, a Republican, in a runoff election in 2021, riding the momentum of Joseph R. Biden Jr.’s 2020 victory in Georgia and helping Democrats to flip both Senate seats. But Georgia reverted to its traditionally Republican status in 2024, backing Mr. Trump. That has put Mr. Ossoff in the perilous position of running as a critic of the president while needing to court his voters, and Republicans view his seat as a prime pickup opportunity.
“Senator Ossoff will defeat any challenger,” Mr. Ossoff’s campaign manager wrote in a statement, suggesting that Mr. Ossoff could build an insurmountable advantage while Republicans scrambled “to outmaneuver each other and audition for Donald Trump’s support.”
Mr. Carter, a six-term congressman who represents southeastern Georgia, including Savannah, ran a pharmacy for decades before running for office, where he has advocated for lowering prescription drug prices.
He has positioned himself as a staunch Trump ally, and introduced a bill earlier this year that would authorize Mr. Trump to purchase Greenland and rename it “Red, White and Blueland.”
