(Bloomberg) -- Iowa voters will brave historically frigid temperatures and snowy roads as they cast their picks for the Republican presidential nomination Monday – marking the official start to the 2024 election cycle in the US.

The results of the Iowa caucuses are vital to the campaigns of Nikki Haley and Ron DeSantis, who strive for a strong showing to halt frontrunner Donald Trump’s march to the nomination. The former president is hoping for a blowout win that will allow him to quickly wrap up the race, especially as his legal woes – which have frequently pulled him away from the campaign trail – start to build.

Here’s what to watch:

Frigid Weather

Iowans are used to the cold, but the forecast is expected to be the coldest in the history of the event. Temperatures could hit as low as -13F (-25C), which could dampen turnout. Candidates over the weekend moved events online or postponed them. 

Aides for all three campaigns expressed confidence in their prep work and turnout operations.

Poll Position

A Des Moines Register/NBC News/Mediacom poll released Saturday showed Trump drawing 48% of support. Haley moved into second place with 20%, and DeSantis slid into third with 16%.

Pollster J. Ann Selzer said in an interview Monday with Bloomberg News that Trump leads among every demographic — particularly among first-time caucusgoers. 

"It's an above average performing group for him," Selzer said. "It's Trump who has gone out and brought in new voters, and I think that is the primary reason his numbers overall are so high."

The survey also revealed an important metric in the face of the inclement weather: enthusiasm. About half of Trump’s supporters said they were extremely enthusiastic about caucusing for the former president. But only 9% of Haley’s backers said the same. Twenty-three percent of DeSantis supporters say they’re extremely enthusiastic.

The base of each candidate varies as well given the disparate strategies. Trump’s Iowa ambitions rely on blue-collar industrial towns. DeSantis is targeting conservative evangelicals in the rural west. Haley’s plan for success runs through the Des Moines suburbs.

With Trump’s lead so commanding, it could lead to complacency among his supporters, who skew older — so we’ll see if the poll holds true Monday night.

Iowa Republicans are motivated to participate in the presidential nominating caucus, animated by concerns about immigration and the economy,  Republican Party Chair Jeff Kaufmann said Sunday.

Read more:  Swing-State Voters Put Border Before Mideast, Ukraine Conflicts 

What’s Next?

Trump, Haley and DeSantis are each looking for momentum to catapult them to New Hampshire’s Jan. 23 Republican primary. Former New Jersey Governor Chris Christie’s move last week to suspend his presidential bid increased the stakes there, since that was where he enjoyed the most support. 

Polls show Haley within striking distance of Trump in the state. A Haley win would undermine the sense of inevitability of a Trump rematch with President Joe Biden in November. But failing to rise to the occasion could be the beginning of the end for her campaign.

DeSantis has struggled in the Granite State, with just 7% support in this month’s Emerson College Polling/WHDH New Hampshire survey. 

--With assistance from Gregory Korte.

(Adds Selzer comment starting in second paragraph under Poll Position subhead)

©2024 Bloomberg L.P.