AMNA NAWAZ: Welcome to the "News Hour" from inside the Republican National Convention here in Milwaukee.

Tonight, the stage behind us belongs to J.D.

Vance, who will headline the evening and accept his party's nomination for vice president.

GEOFF BENNETT: Last night belonged to Donald Trump's one-time rivals in the bruising primary race making peace with the nominee and urging the party to put aside its differences.

Lisa Desjardins starts our coverage tonight from the floor.

LISA DESJARDINS: As we have got ready for day three, last night, it felt like the convention started to find its energy with a night of big speakers and one big message.

A night to unite the party.

GOV.

RON DESANTIS (R-FL), Presidential Candidate: Let's send Joe Biden back to his basement and let's send Donald Trump back to the White House!

(CHEERS) (APPLAUSE) LISA DESJARDINS: Former rivals of Donald Trump, now eager allies.

GOV.

RON DESANTIS: Donald Trump has been demonized.

He's been sued, he's been prosecuted, and he nearly lost his life.

We cannot let him down and we cannot let America down.

LISA DESJARDINS: A political 180 from those who were critics just months ago.

GOV.

RON DESANTIS: Nobody is entitled to be nominated, nobody, especially anybody that couldn't even stop Joe Biden.

FMR.

GOV.

NIKKI HALEY (R-SC): Donald Trump was totally unhinged.

Unhinged.

LISA DESJARDINS: Most closely watched, former presidential candidate Nikki Haley.

She was not initially set to speak here after she held off on endorsing Trump for months.

But, on stage, she left zero doubt.

FMR.

GOV.

NIKKI HALEY: I will start by making one thing perfectly clear.

Donald Trump has my strong endorsement, period.

(CHEERING) (APPLAUSE) LISA DESJARDINS: Haley is important, but the convention knows her voters are even more so, representing a spectrum of never-Trump to no thank you.

She spoke to them directly.

FMR.

GOV.

NIKKI HALEY: You don't have to agree with Trump 100 percent of the time to vote for him.

(CHEERING) (APPLAUSE) FMR.

GOV.

NIKKI HALEY: Take it from me.

I haven't always agreed with President Trump, but we agree more often than we disagree.

LISA DESJARDINS: And she went further, challenging the party to look beyond Trump's MAGA base.

FMR.

GOV.

NIKKI HALEY: To my fellow Republicans, we must not only be a unified party.

We must also expand our party.

LISA DESJARDINS: It was also a family affair.

Trump's daughter-in-law and RNC co-chair, Lara Trump, stressed his immediate actions after Saturday's assassination attempt.

LARA TRUMP, Co-Chair, Republican National Committee: Millimeters separated him from life and certain death.

And yet it was in the midst of it all, as he was jostled offstage by Secret Service, that he knew how defining that moment would be for our country, and he hoisted his fist in the air.

(CHEERING) (APPLAUSE) LISA DESJARDINS: House Majority Leader Steve Scalise, who survived a politically motivated shooting in 2017 himself, added a poignant note.

REP. STEVE SCALISE (R-LA): Not many know that, while I was fighting for my life, Donald Trump was one of the first to come console my family at the hospital.

(CHEERING) (APPLAUSE) REP. STEVE SCALISE: That's the kind of leader he is.

LISA DESJARDINS: But amid praise of Trump, on a night focused on law and order, Republicans generally ignored Trump's own 34 felony convictions, except as evidence of what they see as a weaponized justice system.

SAVANNAH CHRISLEY, Reality TV Star: Today, we have a two-faced justice system.

Just look at what they're doing to President Trump, all while, let's face it, Hunter Biden is roaming around free and attending classified meetings.

KATIE SANDERS, Editor in Chief, PolitiFact: So this is unproven.

LISA DESJARDINS: We spoke with PolitiFact's Katie Sanders.

The organization is checking statements made at both 2024 conventions.

In this case, the claim comes from an NBC report about Hunter Biden.

But: KATIE SANDERS: That report did not say anything about Hunter Biden attending classified briefings.

That would be something that would be illegal, because he does not have a security clearance to be in those sessions.

So it's not a proven claim.

LISA DESJARDINS: Last night, a barrage of statements were also made about immigrants and the border.

Some, PolitiFact found to be true, like this one from Anne Fundner, whose son died of fentanyl poisoning.

ANNE FUNDNER, Mother of Fentanyl Victim: We have seen the highest number of fentanyl deaths during the Biden/Harris administration.

LISA DESJARDINS: But several other statements didn't hold up, like this from Scalise: REP. STEVE SCALISE: On the border, Biden and Harris opened it up to the entire world.

Prisons are being emptied.

KATIE SANDERS: This claim is false.

Joe Biden and Kamala Harris have not opened up the border.

Even more egregious here is the idea that there's an organized effort to recruit people from prisons in other countries.

We have done research to look into whether it's been documented that these governments, these countries, there's some group that's organizing prisoners and releasing them to the U.S.

It's just not proven.

LISA DESJARDINS: On the campaign trail, for his first official solo event, just over a mile from the Convention Center was a jocular GOP V.P.

nominee, J.D.

Vance.

SEN. J.D.

VANCE (R-OH), Vice Presidential Candidate: I joke with the president that I'm very excited about this evening and I don't plan to screw it up, but, if I do, it's too late.

He made the pick, right?

LISA DESJARDINS: As for the man at the top of the ticket, former President Trump prepared for his biggest moment of the week taking a look at the convention podium, the first podium he's stood at since he was shot behind one Saturday.

He's slated to speak from here tomorrow night.

And something that you may see more of on the convention floor tonight, you can see behind me some delegates are actually using paper and putting bandages on their ears, symbolic, of course, of the assassination attempt.

This is the Arizona delegation.

I see several people doing this.

For folks who want to follow live, PolitiFact will be live fact-checking tonight's speeches, and I recommend folks go to our Web site, PBS.org/NewsHour, to follow that.

They're doing a lot of work on that -- Anna, Geoff.

GEOFF BENNETT: Lisa, we are set to hear from the Republican vice presidential nominee, J.D.

Vance, later this evening.

What should we expect to hear from the senator?

LISA DESJARDINS: This is a critical moment for this campaign.

We have a vice presidential nominee who really isn't very well-defined yet.

He's going to have to define himself tonight.

Given what he told people at that campaign event earlier today, just down the street or about a mile-and-a-half away from where we are, he spent a lot of time talking about how he hopes to appeal to working-class Americans, especially Americans in Appalachia.

He also spent a lot of time talking about the media.

So, I think he is going to go on the attack even more against the media.

We expect former President Trump to continue to do that too, but almost the first words out of J.D.

Vance's mouth today to those around him were, the media has been telling lies about Donald Trump.

So, it's traditional for a vice presidential nominee to go on the attack, and we may see some of that tonight.

AMNA NAWAZ: And, Lisa, as you reported, and we saw here in the room, when Vance was first announced, delegates still seemed largely unfamiliar with him.

Is that still the case?

And what does the Trump campaign hope that he will do for them?

LISA DESJARDINS: It is.

There is still uncertainty from delegates here about who exactly J.D.

Vance is.

And I did hear something new today talking to just one or two delegates.

This is a group of people who are largely anti-abortion.

They want abortion restrictions across the country.

This is the reason that Roe v. Wade was overturned, largely people in this room.

But there is some nervousness here that perhaps he could be seen as being too conservative on abortion.

His position has changed in different times.

But his most recent position was actually taken off of his Web site, according to a reporter from The Huffington Post.

So there is some question about whether perhaps he may not bring on board those kinds of voters that Nikki Haley was reaching out to.

Others, though, love him.

They think that he might be the kind of sort of full-blooded attack dog that they want to see, not the calmer tone, but this is a group that, as you said, has been chanting "Fight, fight" for the last couple of days.

One other note, people who are not here, Mike Pence and also Speaker -- former Speaker Paul Ryan.

We don't expect them to attend.

And it's fascinating that we have a vice presidential nominee here tonight with the two former, last, most recent vice presidential nominees apparently not feeling welcome or deciding not to be here.

GEOFF BENNETT: Lisa, the theme tonight is "Make America Strong Again."

In terms of what?

Tell us more about this focus.

LISA DESJARDINS: Right.

Tonight it's going to be about the military, defense.

And we're also going to hear themes about energy.

I do want to point out some of these speakers, it's important to note they're Gold Star families.

They're going to have harrowing and touching stories that Republicans think are important.

But there are also some that I talked to that are on the election denial spectrum.

One of those people is David Lara.

He's a delegate from Arizona.

I spoke to him yesterday.

He was involved in the production of "2000 Mules," largely a conspiracy theory movie.

He was able to find a case of ballot harvesting that was real.

That was -- there was a conviction for harvesting of just four ballots in Arizona.

But based on that one case, a lot of conspiracies came out.

I talked to him yesterday, still an election denier.

He will be talking about immigration today, but it's just to show that there is still a lot going on beneath the surface of this convention.

AMNA NAWAZ: Lisa, we saw the former president, former President Trump, in this arena earlier at the podium doing a walk-through.

And of course, he still had that bandage on his ear reminder of what he endured just a few days ago.

Where does that investigation into the attempt on his life now stand?

LISA DESJARDINS: A bit of news.

First of all, Republican Senate Leader Mitch McConnell just in the last few minutes has asked for the Secret Service to get new leadership, this as we know there's been a subpoena issued by the House Oversight Committee for the Secret Service director to appear next week.

Also, the Department of Homeland Security inspector general, I believe, is launching an investigation into that as well.

GEOFF BENNETT: Lisa, as we have been speaking, we have learned that President Biden has tested positive for COVID and won't be delivering a speech, as planned today, in Las Vegas.

Meantime, earlier today, a top Democrat came forward and said that President Biden should withdraw from this race.

Tell us more about who it is and what this member of Congress had to say.

LISA DESJARDINS: There was a pause on these kinds of calls after the assassination attempt, but now Adam Schiff, top Democrat in the House and Senate candidate from California, issued this statement, writing that: "A second Trump presidency will undermine the very foundation of our democracy.

And I have serious concerns about whether the president, President Biden, can defeat Donald Trump in November."

That is probably the most senior member of the House leadership to openly call for Biden to step aside.

We will have to wait for the response from the Biden campaign and White House.

AMNA NAWAZ: That is our Lisa Desjardins live on the convention floor for us.

Lisa, thank you so much.

LISA DESJARDINS: You're welcome.