ATLANTA — Former president Donald Trump unleashed a fusillade of personal and sometimes false attacks against the popular governor of Georgia on Saturday night, reigniting an intraparty feud three months ahead of the presidential election in this battleground state.

At a rally where his advisers wanted him to sharply attack presumptive Democratic nominee Kamala Harris and focus on Democratic policies, Trump repeatedly veered off script to attack Republican Gov. Brian Kemp in personal and increasingly aggressive terms — and seemed fixated on the past.

Trump mocked him sarcastically and called him “Little Brian”; repeatedly called him “disloyal”; blamed Kemp for Trump being charged in Georgia by a prosecutor whom Kemp has criticized; suggested Kemp wanted Republicans to lose elections; and argued Georgia would have better crime and economic numbers if Kemp were no longer governor.

Even for Trump — who has resented Kemp since the governor refused to help him overturn the 2020 election results and disputed Trump’s false claims of fraud — the broadsides were particularly hostile. They were also delivered in a swing state where Kemp has won office twice by large margins, including a second gubernatorial term in 2022 with Trump opposing him and rallying against him. Trump lost the state by about 12,000 votes in 2020.

“He’s a bad guy, he’s a disloyal guy and he’s a very average governor,” Trump said near the end of his rally, one of about a dozen times he blasted Kemp.

Kemp responded on X, the social media site formerly known as Twitter, during the rally. He was not there in person, and a person close to the former governor said he was not invited to the rally.

“My focus is on winning this November and saving our country from Kamala Harris and the Democrats — not engaging in petty personal insults, attacking fellow Republicans, or dwelling on the past,” Kemp wrote. “You should do the same, Mr. President, and leave my family out of it.”

Kemp has repeatedly sought to temper tensions with Trump, but the two men have not spoken since the weeks after the 2020 election. When Trump attacked him in 2022 and held events for GOP challenger David Perdue — a former senator who lost to Kemp by more than 50 percentage points in that year’s primary — Kemp would generally not respond and say that it was a one-sided war.

Kemp’s team hoped for a détente after that election, noting Kemp has repeatedly avoided criticizing the former president and believing Trump would see Kemp’s large win as a reason to back off.

In recent weeks, Kemp annoyed Trump by saying he did not vote for Trump in this year’s GOP primary — even though Kemp said at the Republican National Convention that he will support the GOP ticket this fall.

One person close to Kemp, who like others spoke on the condition of anonymity to describe private conversations, said the governor had no idea what specifically prompted the attacks on Saturday night. The person said “the chances are about zero” that Kemp will appear with Trump this fall, even if Trump wanted him to do so. Kemp had weighed helping Trump this fall, if asked, and potentially even appearing with him at events.

Some Georgia political strategists have said Kemp has a far better ground game in the state than Trump does, and Trump could use Kemp’s help.

Bobby Saparow, the campaign manager for Kemp’s 2022 race, said the attacks were “ill-willed and ill-timed.” Saparow said the campaign infrastructure that Kemp built in Georgia was critical to winning the state; Kemp won by 7.5 points in 2022 over Democratic opponent Stacey Abrams.

“The bases are solidified. We’re fighting over a very small sliver of voters in the middle. That’s the reason Brian Kemp is the most important Republican to the general election in Georgia in November,” Saparow said.

One person familiar with Georgia politics said Republican elected officials were frustrated because they believe the remarks will hurt Trump and could cost him the state. “Republicans were lined up to give positive comments tonight, and now some of them are scared to,” the person said.

“Makes absolutely no sense at all,” a second person involved in Georgia politics said. “Unless Trump wants to lose the state.”

The person said Kemp still disagrees with the policies of Vice President Harris, who is the presumptive Democratic nominee.

In 2021, Republicans privately blamed Trump for costing the party control of the Senate by repeatedly raising false claims about the election in Georgia, including pressuring the secretary of state to “find votes.”

Trump has been in a foul mood, some advisers said, because of the momentum and media coverage of Harris’s last-minute presidential campaign, which launched after Biden decided to step aside following a stumbling June debate performance. Trump has privately complained about having to face Harris and has been dismayed by polling numbers that show her closing a gap that Biden faced.

His team has sought to unify the Republican Party, knowing they need moderate Republicans in states like Georgia and Arizona to vote for Trump. On Saturday night, he attacked other Republicans, such as former House speaker Paul D. Ryan (Wis.), who have refused to kiss the ring. He mocked Sen. Mitt Romney (Utah) for losing the presidential election in 2012. He attacked Brad Raffensperger, the Georgia secretary of state, who certified the 2020 elections.

Trump also explained how he decided whether to support or revile someone.

“I have a bad trait,” Trump said. “I only like people who like me.”

Several people close to the former president described the comments as unhelpful but said Trump was never going to forget or forgive when it came to Kemp.

The crowd, full of Trump loyalists who waited in the scorching heat for hours, did not seem to mind his attacks on their governor. But they represent the most avid Trump supporters, not the suburban Atlanta voters where Trump bled support from 2016 to 2020, partially costing him the presidential election.

Trump and Kemp first clashed in early 2020, when Kemp sought to open the state after the coronavirus hit but before the Trump administration believed it was safe. Trump was also angry that Kemp was not deferential enough to him in 2019 when he appointed Kelly Loeffler as senator for the state.

Trump also expected him to sign a bill in late 2020 that would have helped Trump investigate that year’s election. Kemp would not sign the bill, surprising the former president, he said at Saturday’s rally. Trump told the crowd a story of sending a young aide to pressure Kemp.

“I got him elected, give me a break. Of course he will,” Trump said. He said he asked Kemp again to sign it and Kemp would not.

Others in the state, he said, were more willing to go along with his false claims of a stolen election — naming several of the people and asking the crowd to applaud them.

“Kemp is very bad for the Republican Party,” he said.

Trump blamed Kemp for his being charged by Fulton County District Attorney Fani T. Willis (D) with conspiring to overturn the 2020 election while mocking her name and the romantic relationship she had with a special prosecutor that has delayed the case. Kemp could have shut down the investigation with a “phone call,” he said.

“Fani Willis is a good friend of your governor. I’m not a fan of your governor,” he said.

Kemp was interviewed by Willis and cooperated in the probe, but the two are not friends and Kemp has been critical of her at times, calling it a politically motivated investigation.

At one point, Trump read about violent crimes in Atlanta and blamed Kemp for the violence. Crime, while a problem in Atlanta, has dropped in recent years, statistics show.

“Atlanta is like a killing field” and Kemp should do something about it, he said to applause from the crowd.

He briefly attacked the governor’s wife, saying she promised they would be indebted to him for the endorsement he gave Kemp in 2018. Marty Kemp, the first lady, is a pivotal adviser to the governor politically but recently said she did not support Trump and would write her husband’s name in instead.

He later told stories about his role in getting Brian Kemp elected, which are exaggerated, according to those close to Kemp. “Disloyal guy,” he said.

Onstage, Trump told Perdue — who gave a loud speech that struck longtime Georgia observers as uncharacteristic of his rhetorical style — that recommending Trump endorse Kemp was one of his only mistakes.

“This was probably the only mistake of David’s life,” he said. He then added sarcastically: “Thanks, David, I appreciate it.”