Weeks of inter-campaign bickering will likely come to a head Wednesday night when Florida Gov. Ron DeSantis and former South Carolina Gov. Nikki Haley meet face to face in downtown Miami for the third Republican primary debate.

Both contenders are trying to pitch themselves as the most viable alternative to former President Donald Trump, who has long held the front-runner spot in the GOP primary.

That struggle has become more bitter as recent polls have shown Haley gaining on DeSantis in the early voting states of Iowa, New Hampshire and South Carolina.

“I think both Haley and DeSantis have given up on trying to cut into Trump’s rock-solid support and [are instead] doing what they can to claim the No. 2 spot in the event that Trump’s candidacy implodes,” Northeastern University political science professor Costas Panagopoulos told The Post.

Trump has 91 pending counts against him across four indictments, a fact both Haley and DeSantis have suggested would be a major liability for Republicans in next year’s general election.

For now, however, Trump’s support among the party faithful has only solidified as his legal troubles mount.

As of noon Wednesday, the 77-year-old had a monster 43.7 percentage-point lead over DeSantis in the RealClearPolitics aggregate.

But Trump’s legal situation is unprecedented for a party’s presidential front-runner, and with three of his four trials currently scheduled for 2024, both Haley and DeSantis could reap the rewards if the former president’s campaign becomes bogged down in courtrooms.

DeSantis’ campaign believes the Florida governor “is the only candidate that has appeal on both the Trump and non-Trump sides of the party,” according to a recent campaign memo.

“Simply put, without Ron DeSantis in this primary, Trump is the Republican nominee. Nikki Haley and others are, at best, simply playing the role of spoiler — exponentially increasing the odds of a Trump nomination,” DeSantis’ team wrote.

The 45-year-old got a boost Monday after Iowa Gov. Kim Reynolds gave him her highly coveted endorsement, a move that has rankled Trump.

DeSantis allies believe Reynolds’ backing could give the governor crucial momentum as he tries to come from behind and overtake Trump in the Hawkeye State’s Jan. 15 caucuses.

On the other side, Haley’s campaign believes she is better positioned for the long haul because of her second-place standing in New Hampshire and her home state of South Carolina..

The Haley campaign has also highlighted internal DeSantis polling indicating that she is the second choice for most of his voters in those two early states.

“EVEN IF DeSantis were to do well in Iowa, which is a big ‘if’ given his current decline, he is in such a weak position in New Hampshire and South Carolina that it doesn’t matter. He has no end game,” Haley’s campaign manager Betsy Ankney wrote in a recent memo.

Haley, 51, is no stranger to tangling with rival candidates onstage.

At the second primary debate in Simi Valley, Calif., she got into it with both biotech entrepreneur Vivek Ramaswamy and her fellow South Carolinian, Sen. Tim Scott.

With the exception of a brief spat over fracking during the same debate, DeSantis and Haley have largely refrained from directly attacking each other.

However, many observers think that will change Wednesday night.

“We all know what will happen,” Scott’s campaign manager Jennifer Decasper predicted in a recent memo. “Nikki Haley and Ron DeSantis will devolve into a slugfest.”

“Candidates in the same party oftentimes have a tough time differentiating themselves on the basis of policy positions,” Panagopoulos said. “Landing a few punches during a debate can be a way of breaking the impasse.”

But there are risks.

“Mudslinging can also devolve very quickly. Sometimes, both combatants get hurt in a knife fight,” Panagopoulos added.

Veteran Republican strategist Mike DuHaime, who is advising former New Jersey Gov. Chris Christie, believes that by attacking each other, DeSantis and Haley would be “doing Trump’s work.”

“Eventually, to beat Trump, they will need to have the courage to go after him the way Christie has,” DuHaime said.

Trump’s campaign has been content to cheer on the fighting from the sidelines, using the former president’s pet nicknames for both in the process.

“A new ad by Nikki ‘Birdbrain’ Haley eviscerates Ron DeSanctimonious on his troublesome record of being against fracking and drilling,” read a recent email blast from the Trump campaign, showcasing an attack video against DeSantis.

Political strategist Rina Shah believes both Haley and DeSantis have legitimate strategic reasons for not wanting to dwell too much on the front-runner.

“I don’t think either of them are going for second place,” Shah told The Post. “I do think they still see an opening here.”

“[Haley] can’t come out with an all-out assault on Trump because she’s seen what that did to [former Arkansas Gov.] Asa Hutchinson’s campaign, she’s seen what that did to [former Texas Rep.] Will Hurd’s campaign.

“Trump continues to poll high amongst likely voters on the Republican side,” Shah added. “And secondly, it’s linked to fundraising. She still wants to be able to get donations from those folks.”

With DeSantis, Shah believes, “he understands that he appeals to the MAGA universe of voters because of the cultural issues — he’s already done that.”

Shah contends that DeSantis needs to concentrate on figuring out a way to broaden his appeal to the GOP electorate.

“Gov. DeSantis is on home turf and the candidates are coming into his house,” said Kristin Davison, COO of DeSantis-supporting Never Back Down. “He will have a great platform to talk about what he has said he would do and what he then achieved.

“His victories in 2022, especially in Miami-Dade County, were what had so many people talking about him running for president in the first place,” she added. “His record as a winner will carry even more meaning tonight, after many Trump-endorsed candidates disappointed across the country last evening.

“On the other hand,” Davison went on, “Nikki Haley is not aligned with where the party is and where the country is today. She is running a campaign that is set for 2008, not one that is set for 2024.”

Diana Glebova contributed to this report.