Six months out from the 2016 horserace getting serious in the frozen tundra of Iowa, the Republican presidential race is as hot as corn-on-the-cob and deep-fried Twinkies -- with virtually the entire field passing and clashing through the Iowa State Fair. 

After a weekend dominated at the fairgrounds by the two parties' respective front-runners, Hillary Clinton and Donald Trump, other key candidates -- with much on the line -- were rolling through Monday. 

One, Scott Walker, is fighting to stay in the top tier after watching his numbers slip following the recent primary debate. Another, Carly Fiorina, wants to keep the momentum going after getting a boost from her standout performance on the same stage. 

Standing on the Iowa stump in short sleeves, jeans and an unbuttoned periwinkle shirt, Walker on Monday sought to remind the first-in-the-nation caucus audience why he stands out in the crowded field. 

"There's only one candidate that's ran who has fought and won and gotten results ... and did it without compromising on common-sense conservative principles," Walker said, referring to his successful election, recall election and re-election. "If you want someone who can win ... I'm the candidate." 

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His remarks were punctuated with applause and boos from the rowdy crowd. Some wore 'cheesehead' hats in solidarity with the Wisconsin governor; others shouted things like "you failed your state." 

Walker said he was "unintimidated" by those opposing him. 

Walker has seen his numbers dip, in both Iowa and nationally. In the most recent national Fox News Poll, released Sunday, Walker slipped to 6 percent, down 3 points and the lowest support he's received for more than a year. In the same post-debate poll, Trump held almost steady at the front of the field. 

But Fiorina, who by most accounts won the "undercard" debate earlier this month on the Fox News/Facebook stage in Cleveland, more than doubled her support, clocking in at 5 percent. 

Instead of delivering a speech on the Des Moines stage on Monday, the former HP exec just took questions from the audience. Asked about the minimum wage, she said it should be a "state decision and not a federal decision." Asked about oil drilling in the Gulf of Mexico, she said America must be the "global energy powerhouse of the 21st Century." On the Department of Veterans Affairs, she called their treatment of veterans a "stain on our nation's honor." 

With 17 candidates in the Republican field, the Iowa State Fair is playing an even bigger role than in past elections in vetting the contenders -- in an offbeat forum where candidates are judged as much on their willingness to eat foodstuffs on a stick as they are on policy proposals. 

Over the weekend, Trump made a grand entrance, landing his helicopter in athletic fields about a mile away and offering rides to children before he came onto the grounds. Almost immediately Trump was crushed by massive crowds seeking photos, handshakes and yelling encouragement. The pandemonium followed him around for roughly an hour -- and during a stop for a pork chop on a stick. 

"This is beyond what I expected. This is amazing," Trump said. "It's been a day of love." 

Both Trump and Clinton avoided getting up on The Des Moines Register's "soapbox," a place where candidates like Walker deliver remarks and take questions from fairgoers. A candidate can be cheered or jeered, depending on the mood of the crowd and whether supporters or opponents are on hand. In 2011 Republican candidate Mitt Romney declared from the soapbox that "corporations are people, my friend," a line that dogged the former private equity executive. 

The state fair typically draws around 90,000 people daily during its 11-day run every summer, giving presidential candidates the perfect opportunity to meet potential supporters for Iowa's first-in-the-nation caucuses. 

Sen. Lindsey Graham, R-S.C., is set to speak later Monday on the "soapbox." Florida Sen. Marco Rubio and Ohio Gov. John Kasich are scheduled for Tuesday. 

The Associated Press contributed to this report.