Which candidates have most to gain — or lose — in first GOP presidential debate?

Presidential debates can be make-or-break for White House hopefuls, and Wednesday night’s Republican primary showdown in Milwaukee is no different.

Much is at stake for the candidates, who each are looking for a breakout moment that will help them chip away at former President Donald Trump’s commanding lead in primary polls.

Florida Gov. Ron DeSantis told Fox News Digital that he’ll be ready on Wednesday night.

“We’ll be ready to do what we need to do to deliver our message, but we absolutely expect that, and we’ll be ready for it,” DeSantis said in an interview this past weekend.

As the runner-up to Trump in most 2024 polls, DeSantis expects to be the number one target of his rivals on a debate stage that won’t feature Trump, who snubbed the event.

Asked whether his debate strategy includes punching back at rivals on the stage, DeSantis answered, “Yes, that means defending ourselves, but more importantly, showing why we are the leader to get this country turned around.”

The Florida governor is trying to change the narrative after a series of setbacks in the past two months, which triggered weeks of negative stories that spotlighted his campaign’s overspending, staff layoffs, change of leadership and other issues.

But he’s not the only one with a lot to gain, or lose.

Former Vice President Mike Pence, a veteran of two vice presidential general election debates, has been preparing for the first showdown by taking part in mock debates. An adviser who is assisting with those and who asked to remain anonymous in order to speak more freely said Pence “will be very well-prepared.”

Pence, by upholding his constitutional duties and overseeing congressional certification of President Biden’s 2020 Electoral College victory over Trump on Jan. 6, 2021, amid the assault on the U.S. Capitol, has endured the wrath of the former president and plenty of Trump’s most devout loyalists and supporters.

The debate, which is expected to draw millions of TV and online viewers, gives Pence a chance to defend his actions and contrast his positions on other issues with the other GOP contenders.

“We’re ready,” Pence senior adviser Marc Short said in a statement. “We’ve been waiting for this for a while.”

Those rivals include South Carolina Sen. Tim Scott, whose campaign says they’ve brought in people with “deep experience with past campaigns” to help him prepare.

“Tim Scott will share his positive, conservative message on the debate stage in Milwaukee,” Scott’s campaign told Fox News. “This debate is another opportunity to connect with millions of voters across the country and show why Tim has faith in America and why he is the strongest candidate to beat Joe Biden.”

Meanwhile, former New Jersey Gov. Chris Christie – who ran for the 2016 GOP presidential nomination – will be the only candidate on the stage with presidential primary debate experience.

“I’m incredibly relaxed. I’ve been there before,” Christie told reporters this past weekend. “I’ll be the only one on that stage that’s ever done it before. So, hell, if I’m nervous, they should all be petrified.”

Former U.N. ambassador and former South Carolina Gov. Nikki Haley
 has been a staple on the campaign trail in the crucial early voting states of Iowa and New Hampshire as well as her home state of South Carolina since launching her presidential campaign in February. She says that experience has helped her prepare for the debate.

“We have done dozens of town halls in Iowa, New Hampshire and South Carolina. We let them ask every question. That’s the best debate prep you can possibly get. So, we’re going to go up on that stage and have a good time,” Haley said in a recent Fox News Digital interview.

But one candidate who isn’t sweating too much is political newcomer Vivek Ramaswamy.

In a Fox News Digital interview last week, Ramaswamy said that “one of the things I’m focused on is not being overly prepared.”

Ramaswamy’s campaign told Fox News that the candidate has been cramming in a lot of foreign policy briefings and spars with staff during flights to prepare himself for the initial showdown. But they added that Ramaswamy was not partaking in any mock debates. And on Monday, he said he was getting ready for the debate by playing tennis – shirtless – for a couple of hours.

Former Arkansas Gov. Asa Hutchinson and North Dakota Gov. Doug Burgum are hoping a standout performance in Milwaukee will boost their national name recognition and spark life for their so-far fledgling campaigns.

However, it’s unclear if Burgum will be able to attend the debate after being hospitalized Tuesday for an injury he suffered while playing basketball with his staff.

Fox News’ Paul Steinhauser contributed to this report.