GEOFF BENNETT: But, first, Republicans are set to hold the first presidential debate of the 2024 election season tonight.

A field of eight challengers is gathered in Milwaukee for this first face-off, as the current front-runner, former President Trump, is notably absent.

Our own Lisa Desjardins is at the debate and joins us now for a preview of what's to come.

So, Lisa, you have been talking to the various campaigns all day.

What are they telling you?

What should we look for tonight?

LISA DESJARDINS: Well, I have to stress, this is the first Republican primary presidential debate in seven years.

A lot of layers have added up.

It's 100 degrees here in Milwaukee.

This could be a fascinating set of dynamics.

And at the top of that is a look at the stage itself.

Eight candidates will be on stage tonight.

It's a sort of governors club, six of them current or former governors, along with two others.

And at the center of that stage is Ron DeSantis, the Florida governor.

Now, his camp says they expect to be attacked.

They expect that he will be seen as in a different league.

He has double-digit support in some polls, where others do not.

However, there are competitors rising up against him.

And every single other campaign that I spoke to said of Ron DeSantis they believe he has the most to lose tonight.

So this will certainly be a test for him.

And, of course, this is also a test of former President Trump.

He is certainly in the ether here tonight, everyone talking about him.

And it's a case of really can the stage here steal the spotlight from him?

Former President Trump plans to have his own event.

It's a prerecorded interview with Tucker Carlson.

That will appear on the social media site X, formerly known as Twitter.

GEOFF BENNETT: Lisa, so much of the coverage of the Republican race has focused on personalities.

Well, what about policy?

We know the target audience for this debate tonight is the Republican base.

What about the issues?

What issues should we expect to hear debated tonight?

LISA DESJARDINS: That's right.

I think among the issues, actually, there could be some foreign policy discussion.

Vivek Ramaswamy, that kind of upstart businessman who's getting a lot of momentum and attention right now, he has come out with some foreign policy -- decisions and stances that his opponents are criticizing, one of them saying he believes the United States should give less aid to Israel.

Expect former South Carolina Governor Nikki Haley to go after him on that.

That's one policy issue I think we should watch for.

Another one, schools.

Ron DeSantis is well-known, and we have covered on this program the changes in Florida's curriculum, specifically regarding African American history.

Senator Tim Scott, one of the competitors on stage, has openly criticized DeSantis about that, and said this idea that the enslaved benefited from slavery is wrong.

So, that could come up, schools and curriculum.

And then, finally, it's not quite policy.

It's more politics, but the truth is, Geoff, I think former President Trump will come up as an issue of policy, an issue, a test of what these Republicans think of what the former president has said, including about the 2020 election.

And Governor Ron DeSantis will be in the middle of that.

His words last week about Trump and his supporters are something we're going to hear about tonight.

I want to play that, what he said an interview last week, right now.

GOV.

RON DESANTIS (R-FL), Presidential Candidate: Because, if you're not rooted in principle, if all we are is listless vessels that are just supposed to follow, whatever happens to come down the pike on TRUTH Social every morning, that's not going to be a durable movement.

LISA DESJARDINS: Now, DeSantis began his career, he was elevated because he was such a Trump supporter.

But Trump and his supporters say that that was a knock against them.

And, in fact, I talked to some voters here, some Trump voters, who say they don't believe DeSantis' words that it wasn't intended for them, it was about elected officials.

They say they did take that personally.

GEOFF BENNETT: Lisa, as you mentioned, Donald Trump's absence will likely loom over this debate.

You have been talking to his campaign.

What are they telling you?

What is he hoping to achieve with this counterprogramming, this interview he recorded with Tucker Carlson days ago, but that is running tonight?

LISA DESJARDINS: He has a simple goal.

He wants to convince voters that the Republican primary is over.

Let's look at a statement from the Trump campaign today.

They wrote: "President Trump has already won this evening's debate."

Then the campaign went on to write this: "Expect the FOX hosts to show unnatural obsession with President Trump."

Now, I raise this, Geoff, because that's another important layer of this debate tonight.

What is going on here is a test of this boiling now feud between former President Trump and FOX News, his almost headquarters as a conservative candidate.

With him not showing up here tonight, it means a choice for conservative viewers.

Are they going to watch eight Republicans on stage who want to be president, including Trump's former vice president, or are they going to watch him with Tucker Carlson?

Or are they just going to watch video clips tomorrow morning?

It is a test of where information goes to conservatives.

GEOFF BENNETT: Lisa Desjardins reporting for us tonight in Milwaukee.

Lisa, thank you.

LISA DESJARDINS: You're welcome.