ROBERT SIEGEL, HOST:
Tonight the real-estate-mogul-turned-unlikely-politician Donald Trump will formally accept the Republican Party's nomination for president. He will speak to the delegates here the Quicken Loans Arena at the end of the convention that has been filled with drama. Trump will also be speaking of course to the nation.
NPR political correspondent Mara Liasson and NPR political reporter Sarah McCammon, who's been covering the Trump campaign, are with me now. And Sarah, let's start with you. What is the campaign saying about what Donald Trump will say tonight?
SARAH MCCAMMON, BYLINE: His campaign advisers say that he will set a vision for the nation and talk about issues like national security in particular. He'll talk about violence abroad and here at home and lay out his vision for how to deal with that. He's also expected to mostly speak from a teleprompter, from a script but to ad lib at times.
SIEGEL: And Mara, what are you looking for in Trump speech? What does he need to accomplish tonight?
MARA LIASSON, BYLINE: Well, this is the ultimate reality TV show for Trump. So the first thing I'm looking for is, how does he make his entrance? It's hard to top that...
SIEGEL: Monday night appearance.
LIASSON: ...Backlit silhouette on Monday. But no, he has a lot to do because the arc of the convention hasn't built a great foundation for him. There's been a lot of chaos. He has some easy things to do - energize his base, make the contrast with Hillary Clinton. That's been done relentlessly here.
But he also has some heavier lifts. He has to unify the party, something that hasn't been fully accomplished. And he has to get voters who are taking a first look at him or have been turned off by some of his rhetoric and want to take a second look - he has to get them to see someone they can imagine in the Oval Office.
SIEGEL: We have heard from several the Trump's children, and tonight his eldest daughter, Ivanka, will introduce her father. Sarah, what do you know about her from watching her on the trail?
MCCAMMON: In many ways she's been his highest profile advocated and surrogate, even more than his wife, Melania. On the trail she's very poised, very polished in her presentation. Let's - I would expect to see her, as his other children have done, talk about him as a person, try to humanize him a bit. His advisers have said this will be a poignant speech.
SIEGEL: Mara, does he need that?
LIASSON: Yes, I think he does. The Trump kids have been the best character witnesses for him this week. But Ivanka Trump has another goal. In addition to telling some funny, tender stories about her dad, she is his emissary to women and particularly millennial women, young professionals like herself. Right now they are Trump's worst demographic.
SIEGEL: Now, tonight's theme is make America one again. First, what does that mean, and how is it reflected in tonight speakers?
LIASSON: Well, it means that they're going to send an inclusive message after a very us-versus-them convention so far. The most interesting speaker tonight for me is Peter Thiel. He's the first openly gay person to address the Republican Convention. He's a billionaire and a libertarian.
And Trump, you know, has been remarkably quiet about social issues, but he's talked about LGBT people in a way no other Republican candidate ever has. After the Orlando attack on the gay nightclub, he talked about gay people being able to live freely and express their identities.
SIEGEL: And we have to talk tonight about last night's drama, Texas Senator Ted Cruz's decision not to endorse Trump and the boos that that prompted on the floor. Today Senator Cruz is defending that decision. Sarah, what does he have to say about it?
MCCAMMON: Well, he isn't back down. This morning he said to the Texas delegation at a breakfast that he couldn't support Donald Trump because of comments about attacks on his wife and his father during the primary campaign. And he did say though he's not ready to endorse Trump, he said he won't be voting for Hillary Clinton. Basically he's told people to follow their conscience.
SIEGEL: Mara, Ted Cruz is taking a big gamble by doing this.
LIASSON: Huge gamble - what he did was either the longest suicide note in political history, or, as his supporters will say, he took a principled position. If Trump loses big and Cruz can avoid being blamed for the loss, he might be in good shape for 2020. Remember; Ronald Reagan in 1976 at the convention did not endorse Gerald Ford, and look what happened four years later.
LIASSON: That's NPR political correspondent Mara Liasson and NPR political reporter Sarah McCammon and by sheer coincidence the band here in the Quicken Loans Arena in Cleveland at the Republican National Convention. Thanks to both of you.
MCCAMMON: Thank you.
LIASSON: Thank you. Transcript provided by NPR, Copyright NPR.