From left, Chris Christie, Ron DeSantis,  Nikki Haley and Vivek Ramaswamy.
CNN  — 

The stage is shrinking just weeks ahead of the first contests of 2024, as four of the Republican Party’s contenders gather in Alabama for their fourth presidential primary debate.

The candidates set to take the stage Wednesday night are Florida Gov. Ron DeSantis, former South Carolina Gov. Nikki Haley, former New Jersey Gov. Chris Christie and tech entrepreneur Vivek Ramaswamy.

Skipping, as he did the first three clashes, is former President Donald Trump, the dominant front-runner in national and early-state primary polling less than six weeks from Iowa’s January 15 caucuses.

Here are four things to watch for in Wednesday night’s debate in Tuscaloosa, which starts at 8 p.m. ET on NewsNation:

The race to be the Trump alternative continues

With Trump absent, the GOP primary debates have played out as a battle to become the party’s top alternative to the former president. That fight, polls show, is now primarily between DeSantis and Haley.

DeSantis offered a preview of how he’ll seek to position himself against Haley in a recent Fox News interview, saying he is the only “true conservative in the race.”

“I think Nikki Haley really represents the last gasp of a failed establishment,” he said. “She’s out of step with a vast, vast majority of Republican voters. But I think some of those elements are people that really want to take the party back to a failed establishment of yesteryear.”

Haley responded to similar critiques from DeSantis in her own Fox News interview, calling his criticism of her “what a candidate says when they are losing.”

“There is nothing establishment about a candidate who was the tea party candidate who ran for governor,” Haley said on Fox News, seemingly referring to her 2010 gubernatorial victory. “I think he is saying what he has to say because he is grasping at this point.”

Whether either candidate is able to use the debates to elbow the other out of contention for second place in the polls could be the key to determining whether Trump will ever face a serious, one-on-one challenge for supremacy within the GOP.

Is Christie a roadblock or helpful rival for Haley?

Haley and Christie both served as Republican governors, leading South Carolina and New Jersey, as two of the party’s brightest stars long before Trump commandeered the GOP.

As they stand together on the debate stage as rival presidential candidates on Wednesday night, the fresh dynamic of their relationship may offer important clues for the next chapter of the race. In the first three Republican debates this year, Christie and Haley have largely avoided any confrontations with each other, but is a collision coming in New Hampshire?

Christie has centered his candidacy on New Hampshire, hoping independents and moderate Republicans who are eager to turn the page from Trump could salvage his presidential ambitions. But Haley’s path also increasingly rests upon a strong showing in the Granite State as she seeks support from many of the same voters.

They could attack each other. Or, perhaps, Haley could sit back and watch Christie go after her chief rival, DeSantis, which could be a far bigger help for her campaign.

Their respective advisers declined to reveal their strategies, but did not dispute that their dynamic is worth watching tonight.

General election landmines

Abortion has long loomed as a potential general election landmine for the GOP in this post-Roe world – a reality that explains Haley’s careful navigation of the issue, avoiding any commitments to enact a federal ban.

But in recent days, another potential landmine has emerged: health care, the issue Democrats successfully rode to massive 2018 midterm election victories.

Trump lit a fire under the GOP’s long-standing, but failed, efforts to repeal Obamacare last week, when he said on his Truth Social website he was “seriously looking at alternatives” to 2010’s Affordable Care Act.

DeSantis, following Trump’s lead, said on NBC’s “Meet the Press” he would propose a measure to “replace and supersede” former President Barack Obama’s signature achievement, which required coverage for preexisting conditions, expanded Medicaid to cover millions more people, allowed children to remain on their parents’ insurance until age 26 and more.

Republicans have tried and failed for years to implement substantial changes to Obamacare, and the party has largely abandoned efforts to campaign on the issue. Injecting it into the middle of the party’s presidential primary, as Trump did last week, comes with the risk of providing Democrats fodder to once again accuse Republicans of seeking to undermine the health coverage of millions of Americans.

How candidates address that issue – and others potentially fraught with general election consequences – could shape how they are viewed by independents who could prove to be an important segment of the New Hampshire and South Carolina primary electorates, as well as broader views about those candidates’ electability.

Haley vs. Ramaswamy, part four

Ramaswamy, the bombastic entrepreneur, dominated the first debate with his frequent interjections and barbs aimed at onstage rivals – including a memorable exchange with Haley on foreign policy.

That aggressiveness won Ramaswamy a short-lived bump in the polls. But longer term, it’s been Haley who emerged from that skirmish and others in the second and third debates on top.

The two have continued to needle each other on the campaign trail since, and with the smaller set of candidates on stage Wednesday night, it’s all but certain they will clash again. The only question is what issue will provide the spark.