A day after Ron DeSantis’s political operation suffered another major setback — the departure of a chief strategist — the Florida governor ignored the internal turmoil at an event in Iowa and did not take questions from reporters. Perhaps there just wasn’t much left to say.

The group, Never Back Down — a super PAC formed to help Mr. DeSantis take on Donald J. Trump and serve as a powerful shadow campaign with a huge war chest and an influential political team — had lost another key player, the sixth senior leader to depart in recent weeks.

In the months since it was founded, the super PAC has burned through tens of millions of dollars and changed its mission and strategy without much success. Four weeks before the first nominating contests in Iowa, it now faces questions about whether what remains is enough to have an impact, without much time to refocus or rebuild.

So instead, Mr. DeSantis and his allies sought to go on offense against his rivals for the Republican nomination — most notably Mr. Trump, who is cruising in Iowa, and former Gov. Nikki Haley of South Carolina, who is challenging him most directly — something he has struggled to do on the debate stage.

At a packed coffee shop on Sunday in Oskaloosa, Iowa, Mr. DeSantis assured voters that he would bolster the country’s military and said that, in contrast to Mr. Trump, his leadership was “not about entertainment.”

While Mr. DeSantis has sought to project strength and competence on the campaign trail, behind-the-scenes infighting at Never Back Down has frequently overshadowed his efforts.

The group, which had amassed $130 million to support his candidacy, was supposed to be a difference maker. Instead, it has sometimes been a distraction, even as it works to build a formidable get-out-the-vote operation in the early nominating states.

The departure on Saturday of the strategist, Jeff Roe, an influential political consultant who seeded Never Back Down with allies from his firm, Axiom, followed the loss of the group’s first chief executive, Chris Jankowski, just before Thanksgiving. Mr. Jankowski’s replacement, Kristin Davison, was fired in early December, and Never Back Down’s chairman, Adam Laxalt, a longtime friend of Mr. DeSantis, also stepped down this month, as two other senior staff members were fired.

Never Back Down is now in an uncertain place. The group has quickly burned through cash and its new chairman and interim chief executive, Scott Wagner, is a Miami lawyer and close college friend of Mr. DeSantis, rather than a seasoned political operative, although he has been a member of the group’s board. In a post on X, Mr. Roe seemed to place the blame for his resignation on negative comments Mr. Wagner made in a Washington Post article about the fired employees.

Meanwhile, another group of DeSantis loyalists has created a new super PAC, Fight Right, that has been running advertisements against Ms. Haley, who has caught up with or surpassed Mr. DeSantis in many polls. The group’s latest ad referred to Ms. Haley as “Tricky Nikki,” accusing her of pushing “the woke corporate agenda” on immigration. The ad was the latest sign that Mr. DeSantis, who has predicted victory in Iowa over Mr. Trump, has instead found himself in a two-front war, battling Ms. Haley for anti-Trump voters while simultaneously trying to wrest Trump supporters from the former president.

Never Back Down, or N.B.D., had previously handled advertising, but Mr. DeSantis’s campaign — which is not legally allowed to coordinate with the group — suggested that it would focus on turning out voters.

“We have full confidence in the N.B.D. ground game and field operation, which is second to none,” Andrew Romeo, a spokesman for Mr. DeSantis, said in a statement on Sunday. “There is a stellar team in place and we appreciate their independent efforts to fight for Ron DeSantis.”

A spokeswoman for Never Back Down did not respond to a request for comment.

Instead of addressing the recent tumult, Mr. DeSantis sharpened his criticism of Ms. Haley and continued to attack Mr. Trump.

Mr. DeSantis has recently urged voters to question why Ms. Haley has not given a firm answer about whether she would accept a role as Mr. Trump’s vice president, should he offer it after winning the Republican nomination. The implication is that Ms. Haley is aligning herself with Mr. Trump and attacking Mr. DeSantis on his behalf, rather than seeking the nomination herself. On Saturday, the DeSantis campaign sent out an email proclaiming that the governor was “Not Running to Be Anything Else.”

“She owes you an answer to this,” Mr. DeSantis told the audience at a town hall in Concord, N.H., on Friday. It was a line of attack he repeated at another event later that night.

Mr. DeSantis also pointed out that Mr. Trump had not ruled out selecting Ms. Haley during a recent radio interview. “Right now I’m not even thinking about that,” the former president had said when asked about the possibility. “I’ve always gotten along well with Nikki,” he added, but cautioned it was “unlikely” he would pick Ms. Haley. (For his part, Mr. DeSantis reiterated in New Hampshire that he would not run on Mr. Trump’s ticket, saying he could accomplish more as governor than vice president.)

Ms. Haley has poured cold water on the charge without directly answering it. At a stop this month in Sioux City, Iowa, a voter asked if she would serve as Mr. Trump’s vice president. “I’ve never played for second,” she responded. (A spokeswoman for her campaign, Olivia Perez-Cubas, said Mr. DeSantis would “say anything to try to salvage his sinking ship of a campaign.”)

On Sunday in Oskaloosa, Mr. DeSantis did not repeat his criticism. But one of his allies, Mark Chelgren, a former state senator in Iowa, opened the event by excoriating Mr. Trump as “self-serving” for denying his 2020 election loss.

“The reality was, the week prior to absentee ballots going out, he had a debate with Joe Biden, and they both looked immature, selfish and petty,” Mr. Chelgren told voters. “That is why Donald Trump lost the last election.”

As for Mr. Roe and the turmoil with Never Back Down, most voters said they were more concerned with policy differences between candidates rather than political infighting.

Jordan Padgett, an undecided voter, said he had not even heard of Never Back Down. “I know the movie, great movie,” he said, referring to the 2008 action film by the same name.

But Shari Dayton, who is supporting Mr. DeSantis, said the fact that the governor’s PAC seemed to be in disarray could affect how she votes in January’s caucuses.

Hearing the news of the organization’s travails, her eyes widened. “I will have to look into that,” she said. “That’s interesting.”

Shane Goldmacher contributed reporting.