Governor DeSantis’s campaign reset appears to be pushing him further out of line with the Republican electorate, as the governor breaks with most of his own party in saying that President Biden won the 2020 election.

Mr. DeSantis as part of his campaign reset is seeking to make more appearances on news programs toward which he has historically been hostile, a decision that led to his appearance on NBC News airing Monday. In the interview, Mr. DeSantis appears to outright reject claims maintained by President Trump that Mr. Biden did not actually win the 2020 election.

“Whoever puts their hand on the Bible on January 20 every four years is the winner,” Mr. DeSantis told NBC. After being asked to clarify, Mr. DeSantis said of Mr. Trump, “No, of course he lost,” adding, “Joe Biden’s the president.”

One of Mr. Trump’s spokesmen, Steve Cheung, responded to Mr. DeSantis’s statement by saying, “Ron DeSantis should really stop being Joe Biden’s biggest cheerleader.”

The NBC interview marks the most prominent instance during which Mr. DeSantis has expressed his view of the 2020 election. At a campaign rally in Iowa on Friday, he had said that theories about a stolen election “did not prove to be true.”

While Mr. DeSantis did say that it was not a “good-run election” and blamed the leader of the Coronavirus Task Force, Anthony Fauci, for the prevalence of mail-in voting in the pandemic-stricken 2020 election, his affirmation of Mr. Biden’s victory marks a break with the GOP voting base.

Even though none of the many lawsuits filed by Mr. Trump and his allies have been able to support or prove Mr. Trump’s claims of election fraud, 69 percent of self-identified Republicans report believing that Mr. Biden did not legitimately win the 2020 election, according to a new CNN poll. 

This represents a six-point increase from last fall, when 63 percent of self-identified Republicans and Republican-leaning independents reported not believing Mr. Biden legitimately won the 2020 election.

At its highest point in the summer of 2021, 72 percent of Republican voters reported believing that Mr. Biden did not legitimately win the 2020 election.

Mr. DeSantis’s newfound outspokenness about that election, combined with the fact that his statements run contrary to the beliefs of the majority of his party, could create more trouble for his already embattled campaign.

The risk of running against the beliefs of his own party’s voters appears to be calculated as part of a plan to argue that the party needs to move on from Mr. Trump.

“If the election is a referendum on Joe Biden’s policies … we will win the presidency,” Mr. DeSantis told NBC. “If, on the other hand, the election is not about January 20, 2025, but January 6, 2021, or what document was left by the toilet at Mar-a-Lago, if it’s a referendum on that, we are going to lose.”

So far, though, Mr. DeSantis’s campaign reset doesn’t appear to be working. Since mid-July, Mr. DeSantis has fallen to 14.3 percent from 20.5 percent support, according to FiveThirtyEight’s average of polls.

Over the same time period, Mr. Trump has consolidated his lead, increasing his support to 53.3 percent from 52.4 percent in mid-July, according to FiveThirtyEight.