GEOFF BENNETT: Every food imaginable is available on a stick at the Iowa State Fair, but the state's largest gathering also serves up a heaping helping of politics and a summer preview of what's to come in 2024.

Lisa Desjardins has this report from the nation's first race for the Republican presidential nomination.

LISA DESJARDINS: This is Iowa's happy place, where one million people come to taste fried food, contentment, and belonging, and where Republicans running for president... GOV.

RON DESANTIS (R-FL), Presidential Candidate: There's so nice in Iowa in the Midwest, but, normally, all I got to do to get Midwest nice is go to Fort Myers in January.

(LAUGHTER) LISA DESJARDINS: ... have their own comfort zone.

MIKE PENCE (R), Presidential Candidate: President Joe Biden has weakened this country at home and abroad.

GOV.

RON DESANTIS: On day one, we take all Biden regulations and executive orders and throw them in the trash can.

(CHEERING AND APPLAUSE) LISA DESJARDINS: President Biden is the easy target.

Much harder for this field?

Confronting the former president.

DONALD TRUMP, Former President of the United States: So the other candidates came here, they had like six people.

LISA DESJARDINS: Donald Trump has a commanding lead in polls and a killer instinct, swooping into the fair and overshadowing his closest opponent, Florida Governor Ron DeSantis.

This is what all the other candidates are up against, enthralled, standing room overflow crowds watching every step that the former president takes here at the fair.

RAEA KRULL, Iowa Voter: Make America great again is what he was all about.

And I think he was on the way to doing that.

JOANIE PELLETT, Iowa Voter: I'm just a solid Trump supporter.

I love all of his policies.

I love everything that we had for those four years.

LISA DESJARDINS: There's more than voter sentiment.

Team Trump is better organized than in 2016, when he was second in the Iowa caucuses.

They're collecting caucus pledge cards at his events and have troops of volunteers in Trump T-shirts as walking ads.

Can anybody beat Donald Trump in this state?

JIMMY CENTERS, Iowa Political Strategist: It's going to be hard.

The president currently has a significant lead, 24 points by the latest New York Times poll.

But Iowans are willing to kick the tires.

LISA DESJARDINS: Iowa Republican strategist Jimmy Centers notes traditional thinking, that the top three caucus finishers have a shot at the nomination.

But, this year, he thinks it will be two, at most.

JIMMY CENTERS: There is a lane for someone to come up to challenge the former president.

That said, you got to get going and you got to get going fast.

LISA DESJARDINS: Fighting hard for that lane is DeSantis, campaigning on his record in Florida.

GOV.

RON DESANTIS: We are going to safeguard the rights of parents in this country.

LISA DESJARDINS: Including his shakeup of the education system there.

DeSantis' crackdown on how schools can teach about race, slavery and LGBTQ issues is popular with social conservatives.

But those things and his moves to restrict abortion and transgender care have brought sharp reaction from others, like these protesters who have followed him around the state.

For some DeSantis supporters, like the Bahrt family, it's more simple.

They don't trust or want Trump anymore.

MICHAEL BAHRT, Iowa Voter: There are probably four or five other candidates in this race that they say good things, but I think that he has the better chance of winning of any of them.

LISA DESJARDINS: Chances helped by some of the strongest organization in Iowa, including the Never Back Down super PAC backing DeSantis.

He is firmly in second place.

But competition is coming up fast behind him.

Vivek Ramaswamy, a 38-year-old businessman, is surging here.

And as he barnstorms the state as a younger version of Trump, Ramaswamy knows Iowa is critical.

VIVEK RAMASWAMY (R), Presidential Candidate: There's nothing like this.

And so we're counting on this for saying that I get to at least tell the people who I am and what I stand for.

LISA DESJARDINS: He's pitching the idea of Trump without the baggage.

TODD SHANNON, Nebraska Voter: I'm leaning towards Vivek at the moment over Trump.

LISA DESJARDINS: Over Trump?

TODD SHANNON: Over Trump, yes.

The reason why is because he has most -- many of the same policies and in many ways he's more extreme.

But he doesn't make everybody go bat crazy when he talks, right?

LISA DESJARDINS: Problem for Ramaswamy, that voter is from neighboring Nebraska.

In Iowa, someone else is on the radar too.

MARTIN EVANS, Iowa Voter: Well, that guy from North Dakota, I think he'd be a good one too.

LISA DESJARDINS: That would be North Dakota Governor Doug Burgum, a self-made Midwestern billionaire.

He brings an energy expertise and straightforward style.

Do you think former President Trump can be beat here and how?

GOV.

DOUG BURGUM (R-ND), Presidential Candidate: Well, if I didn't think there was a way to win, we wouldn't have entered the race.

So we're entering the race to win the race.

SEN. TIM SCOTT (R-SC), Presidential Candidate: Not on my watch.

LISA DESJARDINS: Also getting buzz, South Carolina Senator Tim Scott.

He goes to the fair this week, but beating him there was the state's former Governor Nikki Haley.

Voters are warm over, but Haley needs to be more people's first choice.

How do you gain ground, especially against former President Trump?

NIKKI HALEY (R), Presidential Candidate: Well, first of all, no one's been paying attention.

We held all our money not to spend it, because families are on vacation and kids are out of school.

It is now open season.

LISA DESJARDINS: Overall, candidates rarely take on Trump directly.

A particular exception... MIKE PENCE: I don't have to tell you about the steady assault on our liberties and our values.

LISA DESJARDINS: ... is his former Vice President Mike Pence, who faces a uniquely difficult problem.

MAN: You're a traitor!

LISA DESJARDINS: Multiple fair-goers accused him of treason for breaking with Trump on January 6 and certifying the official election results.

Pence takes on that charge as a strength.

MIKE PENCE: The American presidency belongs to the American people, and the American people alone.

(CHEERING AND APPLAUSE) MIKE PENCE: And I will always believe, by God's grace, I did my duty that day.

I truly believe it.

LISA DESJARDINS: But his problem remains.

How do you gain ground against him?

MIKE PENCE: Well, I just -- look, I'm -- I just say, stay tuned.

I'm so proud of the record of the Trump/Pence administration.

There are Iowa Republicans leery of the former president or worried his indictments could make it difficult to win a general election.

WAYNE BARB, Iowa Voter: Well, the interesting thing is, if he doesn't get them postponed, it's not going to be.

BRENDA BESONEN, Iowa Voter: My feeling is, Trump and Biden both need to step down.

Let's put it that way.

LISA DESJARDINS: But there are many who still believe Trump's narrative.

TOM FISHER, Iowa Voter: Pence stabbed Trump in the back.

You don't do that.

HEIDI REINHARDT, Iowa Voter: He has to make his entrance.

LISA DESJARDINS: Trump volunteer Heidi Reinhardt told us she loves what he did as president and will vote for him or no one.

How do you know that what he's saying is true?

HEIDI REINHARDT: We don't.

We don't know -- we don't know the other people are saying what they're saying either, but I follow behind him.

(LAUGHTER) LISA DESJARDINS: This is the lethal balancing act for the non-Trump candidates.

Many stay upright by avoiding talking about him, but not all.

FMR.

GOV.

ASA HUTCHINSON (R-AR), Presidential Candidate: Donald Trump is dangerous for our country.

LISA DESJARDINS: Former Arkansas Governor Asa Hutchinson is another Iowa hopeful, the one who is the most outspoken about the risk he sees from Trump.

FMR.

GOV.

ASA HUTCHINSON: He ought to step aside.

LISA DESJARDINS: What do you think is at stake for the party?

FMR.

GOV.

ASA HUTCHINSON: I mean, if we don't get this right, there won't be a Republican Party.

LISA DESJARDINS: In Iowa, a highly unusual fight, at turns raucous, at others wild.

(SHOUTING) LISA DESJARDINS: But these Midwestern voters are carefully considering their options.

CAROL EMAL, Iowa Voter: There's a lot of - - on both sides, a lot of interesting... LISA DESJARDINS: Interesting?

CAROL EMAL: Interesting people on both sides.

KIM TOTTS, Iowa Voter: Plus, even if somebody else doesn't get to be a candidate, they have got a lot of good ideas.

MAN: Right.

KIM TOTTS: So I think, especially for the debates and things like that, everybody needs to be heard.

LISA DESJARDINS: At one of the country's biggest fairs ahead of one of the biggest political contests, there is a clear front-runner hovering, but Iowans are listening to everyone.

For the "PBS NewsHour," I'm Lisa Desjardins in Des Moines.