5 things to watch for in the Iowa caucuses

The 2024 primary season is finally beginning, with Iowa kicking it off with its first-in-the-nation Republican caucuses on Monday.

Former President Donald Trump is the overwhelming favorite to win the state -- and the ultimate GOP nomination -- according to polling tracked by 538, while Florida Gov. Ron DeSantis and former South Carolina Gov. Nikki Haley are battling for second place and projecting confidence they can prove their viability with voters.

History proves that winning the caucuses is far from a guarantee of an eventual presidential nomination, but a strong margin of victory, or even beating expectations, could serve as a serious boost for a candidate heading into primaries in New Hampshire and South Carolina.

Here are five things to watch for heading into voting on Monday night.

If Trump wins -- by how much?

The ultimate victor in Iowa's caucuses looks like it will be Trump, if the months and months of polling is accurate. What remains less clear is how much he might win by.

538's polling average in Iowa currently shows Trump with about 51% support, a roughly 35-point edge over Haley, his nearest competitor, who sits at about 17%. DeSantis has narrowly fallen behind Haley, with about 16%.

Strategists and the campaigns themselves are widely expecting that to be too much ground to make up for either Haley or DeSantis, with allies casting a strong second place as a victory.

"They're viewing me as an underdog. I think that's better," DeSantis said Sunday on ABC's "This Week."

Haley echoed that in a campaign trail appearance later Sunday: "We're gonna go all the way until the last hour because we know what situation we're in."

Trump's team has said anything beyond a 12-point win -- the largest margin of victory ever seen in Iowa -- would count as a blowout. 538's average shows his margin could stretch to three times that amount, but the former president's campaign is wary of setting sky-high expectations for fear that his supporters would no longer be motivated to turn out and the speculation of weakness that could come if those expectations aren't met.

Enthusiasm does appear to be on Trump's side, though. The final Des Moines Register/NBC News/Mediacom Iowa poll found that among likely caucusgoers who said they plan on backing Trump, 82% said their mind was completely made up and 49% said they were "extremely enthusiastic."

Among Haley voters, 63% said their mind was made up and just 9% were "extremely enthusiastic."

Should Trump top 50% and wipe out Haley and DeSantis by dozens of points, he would enter New Hampshire's Jan. 23 primary with a head full of steam and help solidify the narrative that 2024's open GOP primary is anything but. Yet even a 12-point win would mark a massive departure from where polling has estimated the race to be, potentially putting a chink in Trump's armor and putting wind in the sails of his rivals.

Who gets second place?

There are likely to be major consequences for both Haley and DeSantis, depending on where they end up in the Iowa results.

Haley has placed a larger emphasis on New Hampshire, where independent and undeclared voters can participate, giving her a broader Trump-skeptical base from which to draw. But her leapfrogging of DeSantis in the Iowa polling showed that a second-place finish is a real possibility.

Should she finish behind Trump -- and particularly if she's able to get even remotely close to him in the final tally -- Haley would likely establish herself as the top Trump alternative in the eyes of many operatives, journalists and donors as well as anti-Trump voters.

Haley's campaign itself hasn't set any expectations for how she'll do in Iowa, but New Hampshire Gov. Chris Sununu, who has endorsed her, has predicted a strong second-place finish for her in the caucuses.

A third-place finish for her, meanwhile, could be a disappointment for a campaign that has been gaining in public perception and polling since the fall.

DeSantis, for his part, has staked virtually his entire campaign on Iowa, essentially ditching New Hampshire and falling to third place in polls there (after former New Jersey Gov. Chris Christie left the race).

Finishing in second place -- again, especially if the margin with Trump is narrow -- would likely reinvigorate a campaign that has been beset by reports of infighting and falling poll numbers, even if New Hampshire is less favorable.

A third-place showing in Iowa, on the other hand, could only fuel chatter about DeSantis' narrowing path to success.

How much does retail politicking matter?

Crisscrossing Iowa is a tried-and-true tradition for candidates looking to win over caucusgoers. But, like much else in the Trump-era, that old rule may be out the window.

Trump has made just 35 in-person stops across 21 days, according to an ABC News count on Sunday morning. DeSantis, meanwhile, has traveled to all of Iowa's 99 counties, holding 169 events across 61 days. And Ramaswamy has been to every county twice, holding 326 events over 89 days.

Yet it is Trump who is far ahead, while DeSantis and Ramaswamy are running in third and fourth places, respectively.

"It feels like there's two different campaigns going on. There's Trump and his legal battles that he puts front and center as his grievance campaign -- 'they're out to get me, fight the deep state' -- and then there's an actual campaign going on between DeSantis and Haley. But it's only for second place," said David Kochel, a veteran Iowa GOP strategist.

How much does a popular governor's endorsement help?

DeSantis seemingly scored a coup in November when he got the endorsement of wildly popular Gov. Kim Reynolds. Now, with polls showing him in third place, it appears Reynolds' vocal support hasn't swayed many voters.

Haley scored her own endorsement of from popular governor, New Hampshire's Chris Sununu, in December, which she's hoping to translate into a strong finish there, likely on the backs of those who have voted for Sununu in the past.

But while Iowa's caucuses and New Hampshire's primary are not apples to apples, the impact -- or lack thereof -- of Reynolds' endorsement could be a warning sign for Haley, who still trails Trump in polling even as she has closed the gap there.

How does weather impact turnout?

Iowa is going to be under a wind chill warning until Tuesday, and temperatures may not even break above 0 degrees -- certainly not ideal conditions for a crucial caucus day in which they would typically be pushing to rally supporters.

The frigid weather has sparked speculation over whether turnout will take a hit -- and who that would impact most.

On the one hand, some Republican strategists speculated that Trump's supporters are so confident in his margin that they might not brave the weather, considering his victory all but guaranteed. But others wondered whether supporters of Trump's rivals would make the same calculation and that turning out would not blunt his victory, making venturing out in a virtual tundra seemingly not worth it.

There does remain a third option -- that Iowa voters value their caucuses enough that they'll turn out regardless.

"I'm going to go," said Karen Kuster, who is still undecided in the caucus. "I've thought about not going, but I'm gonna go."

ABC News' Nicholas Kerr and Kendall Ross contributed to this report.