At a state party summit, Gov. Ron DeSantis and former President Donald J. Trump both argued that Florida was their turf. For the crowd, Mr. Trump’s assertion seemed to ring truer.
When Gov. Ron DeSantis took the stage at a state Republican Party event in Kissimmee, Fla., on Saturday, he strode in front of a giant screen that proclaimed “Florida Is DeSantis Country.”
Hours later, when it was former President Donald J. Trump’s turn, the backdrop instead broadcast a forceful rebuttal: “Florida Is Trump Country.”
Both men were well received. But by the end of the night, Mr. Trump’s slogan rang truer.
During his speech, Mr. Trump, the front-runner in the Republican presidential primary, aggressively attacked Mr. DeSantis, who once seemed like his most formidable rival. He called Mr. DeSantis names and described him as weak and disloyal to a crowd that laughed at a popular governor who once appeared infallible in his home state.
Yet Mr. DeSantis had not even mentioned the former president in his own speech, even after questioning Mr. Trump’s manhood on a conservative news network this week. Instead, he shied away from his recent outspokenness against his rival and returned to the veiled swipes that characterized the race’s early months.
Mr. Trump and Mr. DeSantis have circled each other on the campaign trail for months but have rarely appeared on the same stage. Saturday’s event, the Florida Freedom Summit, brought their political tussle into full view.
It also emphasized a dynamic that has become one of Mr. DeSantis’s largest political hurdles. Even as his rivalry with Mr. Trump has defined the Republican primary for months, the former president’s grip on the party has not loosened, while Mr. DeSantis has been losing ground.
Mr. DeSantis’s reluctance to single out Mr. Trump on Saturday was all the more striking because the other candidates who spoke throughout the day were willing to do so.
Vivek Ramaswamy, 38, said he was better positioned than Mr. Trump to reach younger voters. Senator Tim Scott of South Carolina said that Republicans had underperformed in multiple elections under Mr. Trump’s leadership.
Mr. Scott also took aim at Mr. DeSantis’s campaign, saying that the governor had entered the race as a “historically strong candidate with all the advantages” but had drastically bled support.
Mr. DeSantis’s falling stature was made evident earlier in the day when six Republican state lawmakers said that they would shift their endorsements from Mr. DeSantis to Mr. Trump, a move first reported by The Messenger.
The defections came days after Senator Rick Scott of Florida, Mr. DeSantis’s predecessor with whom he has a frosty relationship, said that he would back Mr. Trump.
Mr. DeSantis dismissed the significance of the legislators’ about-face.
“Look, this happens in these things,” he told reporters on Saturday after signing the paperwork to file for the Florida primary. “We’ve had flips the other way in other states. It’s a dynamic thing. I mean, politicians do what they’re going to do.”
But Mr. Trump made a point of bringing his new supporters onstage early in his speech, emphasizing how he was chipping away at Mr. DeSantis’s core base.
He also portrayed Mr. DeSantis as having desperately sought his endorsement in 2018, saying that Mr. DeSantis had come to him with “tears flowing from his eyes,” and took credit for his political rise. Mr. Trump has made such attacks a mainstay of his stump speech.
“It’s so disloyal,” Mr. Trump said of Mr. DeSantis’s decision to enter the 2024 race. And voters, he said, “care about loyalty.” The crowd whooped in affirmation.
The crowd seemed to be on Mr. DeSantis’s side only when Mr. Trump discussed the coronavirus pandemic. As he rattled off the states whose Republican governors he believed best handled Covid-19, he conspicuously left out one.
Members of the crowd filled in the blank: “Florida,” they shouted. Mr. Trump simply smirked and shrugged.
During his time onstage earlier in the afternoon, Mr. DeSantis at times appeared to be operating within an alternate reality. He did not acknowledge Mr. Trump’s position in the race. His claim that Florida is “DeSantis Country” — certainly accurate when he won re-election by nearly 20 percentage points last year — ignored polling averages that show Mr. Trump 35 points ahead of him in the state.
And while Mr. DeSantis opened his speech by joking that he did not need a teleprompter, a jab at President Biden, he frequently looked down at his notes as he spoke.
Mr. Trump’s hold on Republicans in Florida was evident at the summit. The audience responded with booming cheers as he rattled off his accomplishments and attacked Mr. Biden. No other candidate received such resounding support.
Mark Spowage, 73, said he had considered Mr. DeSantis a Republican “golden boy” after he received Mr. Trump’s endorsement as governor. But his opinion of Mr. DeSantis plummeted when he announced that he was challenging Mr. Trump — a shift shared by many of Mr. Trump’s loyal followers.
“How does he think he has the right to do that?” Mr. Spowage, a software engineer, asked of Mr. DeSantis. “Because from my position, Trump was ordained, like someone that God has anointed to somehow take responsibility. For him to stand up to Trump, wow.”
Many Republicans in the state have been privately whispering that Mr. DeSantis seems weaker at home than ever before, and Mr. Trump’s allies have said they are recruiting more defectors.
Mr. DeSantis is now regularly ridiculed by his onetime ally, Mr. Trump. Memes poke fun at his unfortunate moments on the campaign trail, includinga controversy over whether Mr. DeSantis wears lifts in his boots. (He says he does not.)
A spokesman for Mr. DeSantis’s campaign pointed out that he still has many more endorsements from state legislators in Florida, as well as in New Hampshire and Iowa, the first nominating states.
Mr. Trump, however, remains widely popular with voters in those states. And though Mr. DeSantis has staked his campaign on a strong showing in Iowa, a recent survey found him tied there with Nikki Haley, the former governor of South Carolina. She has edged him out in polls in New Hampshire as well.
Ms. Haley was originally scheduled to speak at Saturday’s summit but did not attend. Her campaign did not answer questions about her absence.
Mr. Trump will again try to overshadow Mr. DeSantis on Wednesday, when the governor and other G.O.P. rivals take part in the third Republican debate in Miami. The former president, who has announced that he will instead hold a rally in Hialeah, Fla., is skipping the debate once again, a decision Mr. DeSantis sharply criticized earlier this week but did not mention on Saturday.
“If Donald Trump can summon the balls to show up to the debate, I’ll wear a boot on my head,” Mr. DeSantis said in an interview on Newsmax on Thursday.
But the crowd at the summit was clearly in no mood to hear any digs at the former president, and candidates who criticized Mr. Trump were heckled. When former Gov. Asa Hutchinson of Arkansas said that he believed Mr. Trump would probably be found guilty in one of the criminal cases he was facing, the boos were ferocious.
And Chris Christie, the former governor of New Jersey who has become an outspoken Trump critic, was jeered immediately after he took the stage.
Mr. Christie was not dissuaded, firing back at the crowd, “Your anger against the truth is reprehensible.”
Jazmine Ulloa contributed reporting.