In a presidential race that's been underway for more than a year, the voters finally get a say.

Braving frigid below zero temperatures that are punishing the Hawkeye State, Iowans head to more than 1,600 caucus sites on Monday night to cast ballots in the lead off contest of the 2024 Republican presidential nomination race.

"Tomorrow, Jan. 15, I need each and every one of you to get out. Everybody get out. Just get out and vote," former President Donald Trump urged his supporters at a rally Sunday in Indianola, Iowa.

The former president is the commanding frontrunner in national surveys and the latest polls in Iowa as he runs a third straight time for the White House. 

WHAT THE FINAL POLL SHOWS BEFORE MONDAY'S IOWA GOP PRESIDENTIAL CAUCUSES

Trump made history last year as the first former or current president to be indicted for a crime, but his four indictments, including charges he tried to overturn his 2020 presidential election loss, have only fueled his support among Republican voters.

HALEY KNOCKS MEDIA EXPECTATIONS BUT LOOKS TO ‘BIG SHOWING’ IN IOWA

He stood at 50% or higher in a slew of polls over the past month in Iowa and grabbed 48% support in the final Des Moines Register/Mediacom/NBC News poll of likely Republican caucusgoers, which was released Saturday night. Former ambassador to the United Nations and former South Carolina Gov. Nikki Haley and Florida Gov. Ron DeSantis stood at 20% and 16% in the new survey as they battle for a distant second place.

Multimillionaire biotech entrepreneur and first time candidate Vivek Ramaswamy, who has relentlessly campaigned across Iowa in recent months, stood at 8% in the poll. 

The closely watched and highly anticipated survey, conducted by longtime pollster Ann Selzer, has a well-earned tradition of accuracy in past GOP presidential caucuses, and is considered the gold standard in Iowa polling by many.

DESANTIS BETS BIG ON IOWA - WILL IT PAY OFF?

DeSantis and Haley questioned whether Trump would meet lofty expectations.

DeSantis' campaign manager James Uthmeier, in a Sunday appearance on Fox News' "America's Newsroom," argued that "expectations are high for Trump…he's got to perform. If he gets less than half the vote, more people voting against him than for him. I think that's, you know, setting up doom down the road."

And Haley, in an interview on the same program, noted that people will be looking to see if Trump "is falling below 50%."

Longtime Republican strategist David Kochel, a veteran of numerous GOP presidential campaigns and statewide contests in Iowa, told Fox News "there are two campaigns going on in Iowa right now."

"One is Trump vs. his expectations and the other one is Haley vs. DeSantis to see who gets the right to take on Trump one-on-one," noted Kochel, who remains neutral in the Republican presidential caucuses.

Trump and his campaign are taking aim at the high expectations he faces in Iowa.

"No one has ever won the Iowa caucus by more than 12%," Trump campaign senior adviser Chris LaCivita told Fox News Digital on Saturday. "I think the public polls are a little rich."

Trump, speaking with reporters on Sunday, said "there seems to be something about 50%."

"I think they're doing it so that they can set a high expectation. So if we end up with 49%, which would be about 25 points bigger than anyone else ever got. They can say he had a failure, it was a failure. You know fake news," he argued.

Haley, who launched her presidential campaign nearly a year ago, told supporters at an event Sunday in Ames, Iowa, "I know you're excited. I'm excited because it's been 11 months, and it comes down to tomorrow."

Thanks in part to well-regarded debate performances, Haley enjoyed plenty of momentum in the late summer and autumn. In recent weeks, she caught up with DeSantis for second place in national surveys and the polls in Iowa.

Haley also surpassed DeSantis and surged to second place, thus narrowing the gap with Trump, in New Hampshire, the state that holds the first primary and second overall contest in the GOP nominating calendar, eight days after Iowa's caucuses.

Speaking with Fox News Digital late last week following an energetic campaign event in Ankeny, Iowa, Haley touted that "our people are excited. The momentum is real on the ground."

Haley, who has repeatedly in recent weeks tried to frame the GOP nomination race as a two-candidate battle between her and Trump, pointed toward the former president as she told Fox News on Sunday that "it’s you and me now."

IT'S NOT AN ELECTION, SO HOW DO THE IOWA CAUCUSES WORK?

DeSantis stressed "we've done it the right way" while standing in front of a jam-packed room at the Iowa headquarters of a super PAC supporting his White House bid.

The Florida governor has spent much of his time and resources in Iowa and with his presidential campaign arguably on the line in Monday night's caucuses, DeSantis was urging his supporters to brave the bitter cold to show up and vote.

"It’s going to be cold. It’s not going to be pleasant. But if you’re willing to go out there and you’re willing to fight for me, if you’re willing to bring people to the caucus, if you’re willing to brave the elements and be there for the couple of hours you have to be there, if you’re willing to do that, if you’re willing to fight for me on Monday night, then as president I’ll be fighting for you for the next eight years," DeSantis emphasized.

TRUMP TAKES NO CHANCES AS THE IOWA CAUCUSES APPROACH

DeSantis, who was convincingly re-elected to a second term as Florida governor 14 months ago, was once the clear alternative to Trump in the Republican race. 

However, after a series of campaign setbacks over the summer and autumn, and after getting hammered by negative ads, DeSantis saw his support in the polls erode.

Now, he's betting that his vaulted ground game in Iowa, which is heavily reliant on the aligned super PAC Never Back Down, will carry him across the finish line.

"We've got a great path going forward," DeSantis emphasized on "Fox News Sunday." "We're going to do well on Monday. We've got an unbelievable organization."

Some pundits question whether DeSantis will stay in the race if he finishes behind Haley on Monday night.

When asked if he is heading on to New Hampshire regardless of his finish in Iowa, DeSantis reiterated his response from a Fox Digital interview on Friday – "we're going to be in New Hampshire."

Trump, who narrowly lost the 2016 Iowa caucuses to Sen. Ted Cruz of Texas, has dramatically stepped up his campaign operation in the state compared to eight years ago as he aims to quickly wrap up the 2024 nomination.

"We’ve built an operation in over 1,800 caucus locations with straight-up volunteers, neighborhood by neighborhood. They know the area, and they know who’s caucusing in their area, and they’ll be following up with them, making sure they vote," LaCivita told Fox News.

"Our focus and our premium has been on people…and we think it’s going to bear fruit in a big way," he predicted.

Blizzard conditions blasted Iowa on Friday and Saturday, with lingering effects into Sunday.

Longtime Iowa GOP chair Jeff Kaufmann was confident that the frigid forecast wouldn't keep Iowans home on caucus night.

"Out of everything – snow, ice and the cold temperatures – the cold temperatures worry me the least," he told Fox News on Friday.

"If it was today. I would be worried. On Monday, we’re going to have two days of clearing off the roads," Kaufmann noted. "Iowans can handle the cold. And they know exactly what to do to keep themselves safe."

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.