Georgia Governor Brian Kemp, a Republican who’s been a frequent target of former President Trump, will face a primary challenge in his reelection bid next year. Former Georgia State Representative Vernon Jones, a longtime Democratic elected official who endorsed Mr. Trump in 2020 and became a Republican earlier this year, announced Friday that he’ll run against Kemp. 

In his announcement speech outside of the Georgia capitol building, Jones railed against Kemp for not embracing Mr. Trump’s unfounded claims of widespread fraud in the 2020 election. 

“For those of you who feel your voices weren’t heard, for those of you who feel the incumbent governor didn’t fight for you, a new day has dawned,” Jones said. 

His remarks echoed attacks against Kemp by Mr. Trump and his supporters following the 2020 election. Three separate tallies of Georgia’s votes affirmed President Biden was the first Democrat to win the state since 1992.

The former president endorsed Kemp in the 2018 gubernatorial election, but said in a Fox News interview in November that he was “ashamed” to have backed the Georgia governor. During a January rally in Georgia the night before the Senate runoff elections, Mr. Trump said, “I’m going to be here in a year and a half, and I’m going to be campaigning against your governor.” 

Mr. Trump hasn’t endorsed a candidate in Georgia, and it’s not yet clear whether Jones will pose a serious threat to Kemp. Jones has appeared at rallies with the former president and spoke at the Republican National Convention last summer. He recently posted a video from Mar-a-Lago last week in which Mr. Trump asked when Jones “when are you announcing?” 

Jones’ speech on Friday suggested that he plans to capitalize on Mr. Trump’s animosity toward Kemp. 

“There is absolutely nothing the governor can do to change his cut-and-run image in the eyes of 45 and his supporters of Georgia,” Jones said, referring to Mr. Trump as “45,” shorthand for the 45th president. “Make no mistake about it, he is the leader of our party.”

Jones was an elected Democratic former DeKalb County chief executive and state representative, but has a history with scandal. The Atlanta Journal-Constitution last summer published a detailed account of Jones’ checkered past. 

Kemp has tried to reestablish himself with Georgia Republicans since signing a law that overhauled Georgia’s election. He has been a frequent guest on Fox News and criticized corporations that spoke out against the bill, including Major League Baseball, which pulled its All-Star Game out of the state. A Morning Consult tracking poll shows Kemp had a 62% approval rating among Georgia Republicans when he signed the bill on March 25. By April 6, it was up to 74%. 

“Vernon Jones is a lifelong Democrat, voted for Barack Obama, supported gun control, and voted against Georgia’s heartbeat bill,” Kemp’s campaign manager Bobby Saparow said in a statement. “He is not a Republican, and he certainly is not a conservative. Assuming he actually stays in the race, we look forward to contrasting Governor Kemp’s successful conservative record with Vernon Jones’ liberal, corrupt tenure in public life.”

Jones seemed to anticipate the attack over his vote against Georgia’s “heartbeat” bill, which would outlaw abortion once a fetal heartbeat can be detected, generally at around six weeks. The state law was struck down in federal court and is being appealed. In a tweet earlier this week, Jones said, “life begins at conception – period.”

While Kemp’s approval rating among Republicans in his state has jumped since signing the election law, it hasn’t smoothed things over with his chief critic in the GOP. Mr. Trump renewed his attacks on Kemp earlier this week in a pair of statements. The former president called the new law a “watered-down version” of what was initially introduced and said Kemp “caved to the radical left-wing woke mob who threatened to call him racist if he got rid of weekend voting.”

An earlier version of the law banned counties from allowing Sunday voting, a practice historically used by Black churches in the state, but the final version expanded the weekend voting hours that counties were required to offer. 

In his announcement speech, Jones also criticized 2018 Democratic gubernatorial candidate Stacey Abrams, calling her “the wicked witch of the South.” Many Democrats are also  expecting Abrams to run again in 2022.

Kemp isn’t the only GOP incumbent facing a primary challenge in Georgia next year. Representative Jody Hice announced last month that he will challenge Secretary of State Brad Raffensperger. 

Mr. Trump repeatedly attacked Raffensperger after the election and asked Raffensperger to “find” enough votes in the state’s presidential election to overturn the results during a phone call. The former president has already endorsed Hice. 

“Unlike the current Georgia Secretary of State, Jody leads out front with integrity,” Mr. Trump said in his statement. “I have 100% confidence in Jody to fight for Free, Fair, and Secure Elections in Georgia, in line with our beloved U.S. Constitution.”