Having stood out in two presidential debates, Nikki Haley has booked her largest venue in Iowa since launching her campaign. She's hoping to fill a 600-person hall in a western Des Moines suburb on Saturday.

That would be a huge number for most of her rivals. It's also less than the smallest crowds usually drawn by Donald Trump, who is dominating the Republican field for the 2024 Iowa caucuses less than four months away.

The former president will be in rural southeast Iowa the following day to headline an organizing event. Aides were expecting at least 1,000 to attend.

In essence, there are two Iowa campaigns underway: Trump is holding fewer, bigger events that demonstrate the strength of his organization and grip on GOP base voters, while his rivals attend the state's traditional candidate forums and meet-and-greets, searching for ways to cut into his lead or consolidate second place.

While things could change before the Jan. 15 caucuses, some campaigns are trying to shift expectations. They're hoping a close runner-up to Trump in Iowa — or even someone who falls well short of Trump but pulls away from other rivals — could begin consolidating support and force others out.

“What’s crystal clear to me is that until there is a winnowing event, you’re never going to get to the head-to-head that it would require to have somebody other than Trump win the nomination,” said Gentry Collins, who managed Mitt Romney’s campaign for the 2008 caucuses. “That winnowing starts in Iowa and it changes the dynamics of the race.”

Here’s a look at the campaigns working hardest in Iowa to catch Trump.

RON DESANTIS

Campaign overspending and donor jitters prompted the Florida governor to shake up his organization and narrow a broad, national approach to one increasingly focused on Iowa. His national support has slipped substantially from its high point earlier this year.

DeSantis hired David Polyansky as a senior deputy campaign manager in August. Polyansky is a top strategist with Iowa chops from past presidential campaigns. He was working for Never Back Down, the super PAC supporting DeSantis.

Never Back Down has taken on a huge share of work normally done by candidates directly. It has put on almost 50 of DeSantis’ Iowa appearances, hired 22 paid staff in Iowa — more than on any campaign team in the state — and purchased almost $8 million of television and digital ads this year, the most of any single political group, according to analysis from the tracking firm AdImpact.

Speaking on condition of anonymity to discuss internal strategy, two DeSantis advisers suggest he could survive three second-place finishes — in Iowa, New Hampshire and South Carolina — and try to force a head-to-head matchup with Trump ahead of March's Super Tuesday slate of primaries.

DeSantis has already visited two-thirds of Iowa's counties, Polyansky said in an interview, The candidate pledged earlier this year to visit all 99, a goal that could net extra support and allow him to shore up more populous counties down the stretch.

“Knocking out a majority of our 99-county swing this early, before the caucus campaigning heats up even further, gives us the freedom down the stretch to travel where we want to go and when we want to go” in Iowa, New Hampshire and beyond, Polyansky said.

NIKKI HALEY

Haley's team pumped up expectations going into Wednesday's second debate and hopes her energetic performance — including several tussles with rivals — translates to a rise in polls.

She impressed Nicole Schlinger, an Iowa Republican campaign phone and text vendor who has not committed to a 2024 candidate.

“Nikki's showing she can be strong and assertive and put these guys back on their heels,” said Schlinger, who is not committed in the 2024 race.

Toiling before smaller crowds throughout the spring and summer, Haley, the former United Nations ambassador and governor of South Carolina, drew a noticeably more robust 400 to stops in rural eastern Iowa this month. She took the wheel of a combine among amber rows of corn.

She has recently signed noteworthy Iowa GOP talent, including Troy Bishop, who was Iowa Sen. Chuck Grassley's organizational director. And she's lured some donors away from DeSantis, including billionaire former Illinois Gov. Bruce Rauner. Now, the super PAC supporting her is spending more on ads in Iowa.

TIM SCOTT

Scott was striding toward the midway at the Iowa State Fair this summer when a man approached from behind to tell him, “I've seen your ads.”

He wasn't alone. Scott's campaign and the super PAC supporting him have combined to spend roughly $10 million in advertising this year introducing Scott to Iowans, about a quarter of all GOP caucus campaign and super PAC ad spending, according to AdImpact.

The South Carolina senator's team argues Iowans are more familiar with him through advertising and ready to see him emerge in the up-close settings that are traditionally critical here.

He has started criticizing his rivals more, going after Trump, DeSantis and Haley for refusing to push for a federal abortion ban. His more aggressive posture was on display during the Wednesday debate in California, when he criticized a proposal by Haley to increase the gas tax.

“I think I come across as a nice guy. I will say, though, that I am not an angry guy,” Scott told one Iowa audience after being asked if he was tough enough to confront Russia. “I think we sometimes confuse anger with strength.”

VIVEK RAMASWAMY

Long before he grabbed attention at the first debate, Ramaswamy was working hard in Iowa.

The 38-year-old entrepreneur has traveled the state more than any candidate, holding nearly 70 campaign events. He's gotten buzz for his youth and charisma, his lack of political background, and a brashness that reminds some people of Trump. Some Iowans have also voiced unfavorable impressions sparked by what some see as foreign policy naivete and lack of experience.

Ramaswamy's Iowa team is small and led by outspoken social conservative former state Sen. Jake Chapman and former Iowa Secretary of State Matt Schultz.

Ramaswamy, who is Hindu and the son of Indian immigrants, always cites what he calls his lists of truths, the first of which is “God is real." Evangelical Christians are critical in Iowa.

While few will say out loud that Ramaswamy's faith is an obstacle, one voter raised it at a Tim Scott event last week.

"He talks about God all the time, but it's a pagan god,” said Liz Kuennen of Fort Dodge.

Hindus worship several gods, who they believe to be manifestations of the one formless supreme being.

MIKE PENCE

For a former vice president so closely identified with evangelical Christians, it would seem Pence would have a leg up.

Yet Pence faces distinct challenges.

Among the most stubborn is the lingering — and false — perception that Pence could have refused to certify the 2020 election. A man in the state fair crowd this summer confronted Pence and asked him, “Why did you commit treason?”

Pence patiently walked through the constitutional requirements of the vice president during the certification process.

“Even though my former running mate and his outside lawyers told me that authority was there, I knew it never was,” Pence told the crowd. “I’ll always believe, by God’s grace, I did my duty that day.”

Though the now well-rehearsed answer sparks respectful applause, Pence faces stubbornly high unfavorable ratings in Iowa among likely GOP caucusgoers.

Still, Pence, who had seven events planned in Iowa over the coming days, was on track to top 60 campaign stops by the end of next week, second only to Ramaswamy.