With President Trump leading in GOP primary polls and Republicans reeling from three cycles of poor election results, a question is looming: Can Republicans keep Mr. Trump from becoming the 2024 presidential nominee?

After 2022 delivered historically bad midterm election results for Republicans, compounding defeats in 2018 and 2020, many in the party have begun to blame its failures on the former president.

Governor Sununu — himself considered a potential 2024 contender — is one of the few Republicans to publicly and directly question Mr. Trump’s viability as a candidate.

“I don’t think he can win in November of ‘24,” the New Hampshire governor said in a December appearance on CNN. “He could be the nominee. But I do not believe, and I think most people would agree, he’s just going to — not going to be able to close the deal in November of ‘24.”

Republican Party elites have been scrambling to find an alternative for the 2024 presidential nomination, and Florida’s governor, Ron DeSantis, seems to be it.

Top donors have been coalescing around Mr. DeSantis for months, a process that has only accelerated since his standout midterm performance, when he won re-election by a resounding margin while Republicans suffered nationally.

A professor of political science and the director of the Elections Research Center at the University of Wisconsin Madison, Barry Burden, warns that the GOP is in a tight spot.

“It’s a difficult position for Republicans,” Mr. Burden told the Sun. “If they end up nominating someone besides Donald Trump, his history suggests that he will go after them for rigging the nomination.”

The problem for GOP officials looking to keep Mr. Trump away from the nomination is that, unlike the Democrats, there’s no direct way for the party to influence the primary elections.

The Democratic Party changed its nominating process after the disappointing electoral performance of Senator McGovern in 1972 and President Carter’s loss in 1980. After the losses, the party moved to take more control over its primaries, rolling back changes made in 1968 that gave more control to voters and, consequently, less electable nominees in the general election. 

In 1982, the party created superdelegates who vote in the party nomination process but are not beholden to voters. The superdelegates, who make up about 15 percent of the delegate pool, allow party leadership to put their thumb on the scales when they see fit.

The superdelegates are the Democratic Party chairmen and vice chairmen of every state and territory, the 212 committee members, and the party’s elected representatives, senators, and governors. Former national party leaders and presidents are also included.

Republicans have no similar structural way for party elites to steer the party away from nominating a candidate considered to be weak. In the GOP, each state only sends three superdelegates that make up around 7 percent of the delegate pool. Since 2015, they are also required to vote for the winner of their state’s primary.

A professor of political science at John Jay College, Brian Arbour, explains that Republicans still have ways to influence the nomination process, but they’re less direct.

“The other way to look at it is through donations, through finance,” Mr. Arbour told the Sun. “We’ve already seen some of this in support for DeSantis — he’s raised a huge amount of money.”

Mr. Arbour warns, however, that Republicans hoping to prevent Mr. Trump from clinching the nomination will need to coordinate and act as a unified bloc. 

So far, it’s not clear that this is happening, in part because there are other candidates hoping to take the Florida governor’s spot as the non-Trump Republican favorite and in part because Mr. DeSantis is untested on the national stage.

“I do think it’s in the interest of any of the other non-Trump candidates to take DeSantis down several pegs,” Mr. Arbour said. “And frankly we don’t know how DeSantis will play outside Florida or outside a very conservative media environment.”

Aside from reservations about other candidates, Mr. Arbour notes that Republicans, historically, are more suspicious of their own party and less likely to take cues from their party about who to vote for than Democrats.

“Party elites care more about winning elections than the average voter does,” Mr. Arbour said. “It’s unclear whether Republicans can get the electorate to take their cues.”

A successful primary campaign against Mr. Trump would likely create a scenario where the Republican nominee is campaigning against both the Democratic nominee and Mr. Trump, regardless of whether Mr. Trump is on the ballot.

“There are definitely Republicans who are in the party because of Trump and they are attracted to the fact that he is opposing institutions, including their own party,” Mr. Burden said. “There will be Republicans who are diehard Trump or bust.”

Exactly how many Republican voters are Trump loyalists is unknown, but, in Mr. Burden’s opinion, there is little doubt that Mr. Trump would be able to peel off a significant portion of Republican voters if he were to run in the general election as an independent or third party candidate.

Since his presidential win in 2016, many party officials on the state and national levels have been replaced by Trump loyalists, and a perceived rigged primary could turn them and their voters against the national party and its nominee.

In 2016, a similar situation played out in the Democratic nomination process, as more than a quarter of Senator Sanders’s supporters ended up refusing to vote for Secretary Clinton, with more than 10 percent voting for Mr. Trump.