AMNA NAWAZ: Welcome to the "News Hour."

Tonight here at the Democratic National Convention, Minnesota Governor Tim Walz will accept his party's nomination to be vice president and introduce himself to the American people.

GEOFF BENNETT: Last night, it was former President Barack Obama and former first lady Michelle Obama who were center stage, energizing the convention crowd and delivering scathing criticisms of former President Donald Trump's campaign and presidency.

White House correspondent Laura Barron-Lopez joins us now from the convention floor, where she's been watching it all.

LAURA BARRON-LOPEZ: That's right, Geoff and Amna.

The former president threw his weight behind Harris' nomination last night, telling the packed arena here that the Harris/Walz ticket is ultimately the only choice.

With back-to-back speeches that lit up the arena, Barack and Michelle Obama delivered a political one-two punch.

BARACK OBAMA, Former President of the United States: I don't know about you, but I'm feeling fired up.

(CHEERING) (APPLAUSE) BARACK OBAMA: I am feeling ready to go.

LAURA BARRON-LOPEZ: Firing up the crowd for Kamala Harris and warming up a Trump presidency.

BARACK OBAMA: We have seen that movie before, and we all know that the sequel is usually worse.

(CHEERING) (APPLAUSE) MICHELLE OBAMA, Former First Lady: A familiar feeling that's been buried too deep for far too long.

You know what I'm talking about.

(CHEERING) (APPLAUSE) MICHELLE OBAMA: It's the contagious power of hope.

LAURA BARRON-LOPEZ: The former president and first lady captivated Democrats with a message of hope.

Mr. Obama compared the enthusiasm for Harris to his rise 16 years ago.

BARACK OBAMA: I am feeling hopeful because this convention has always been pretty good to kids with funny names who believe in a country where anything is possible.

LAURA BARRON-LOPEZ: But the Obamas also took the fight directly to Trump, repeatedly calling attention to his privileged background.

MICHELLE OBAMA: Most of us will never be afforded the grace of failing forward.

We will never benefit from the affirmative action of generational wealth.

BARACK OBAMA: Here's a 78-year-old billionaire who has not stopped whining about his problems since he rode down his golden escalator nine years ago.

LAURA BARRON-LOPEZ: And this scathing response to Trump's racist birther conspiracy theory that he continues to peddle.

MICHELLE OBAMA: For years, Donald Trump did everything in his power to try to make people fear us.

See, his limited, narrow view of the world made him feel threatened by the existence of two hardworking, highly educated, successful people who happen to be Black.

(CHEERING) (APPLAUSE) LAURA BARRON-LOPEZ: For Michelle Obama, in particular, who said this on the convention stage in 2016... MICHELLE OBAMA: No, our motto is, when they go low, we go high.

LAURA BARRON-LOPEZ: ... her tone last night was different, at one point firing back at Trump's remarks falsely claiming that undocumented immigrants are taking -- quote -- "Black jobs."

MICHELLE OBAMA: Who's going to tell them that the job he's currently seeking might just be one of those Black jobs?

(CHEERING) (APPLAUSE) KAMALA HARRIS, Vice President of the United States (D) and U.S. Presidential Candidate: Do we believe in the promise of America?

AUDIENCE: Yes!

KAMALA HARRIS: And are we ready to fight for it?

AUDIENCE: Yes!

LAURA BARRON-LOPEZ: Vice President Harris wasn't in the audience at the convention, like she was on night one.

KAMALA HARRIS: This is not just about us versus Donald Trump.

This is about two very different visions for our nation.

LAURA BARRON-LOPEZ: Taking a quick trip to Milwaukee, Wisconsin, with her running mate, Tim Walz, campaigning in the exact place Trump accepted his party's nomination back in July.

LIL JON, Musician: We are here tonight to officially nominate Kamala Harris for president!

(SINGING) LAURA BARRON-LOPEZ: While Democrats held a symbolic roll call to celebrate her nomination... GOV.

GAVIN NEWSOM (D-CA): California, we proudly cast our 482 votes for the next president, Kamala Harris.

(CHEERING) (APPLAUSE) LAURA BARRON-LOPEZ: ... Harris beamed in on the JumboTron.

And returning to Chicago, she watched her husband's speech from aboard Air Force Two.

It was second gentleman Doug Emhoff who showed the convention crowd the personal side of Kamala Harris.

DOUGLAS EMHOFF, Second Gentleman: I got Kamala's voice-mail and I just started rambling.

(LAUGHTER) DOUGLAS EMHOFF: Hey, it's Doug.

(LAUGHTER) DOUGLAS EMHOFF: By the way, Kamala saved that voice-mail.

(LAUGHTER) DOUGLAS EMHOFF: And she makes me listen to it on every anniversary.

LAURA BARRON-LOPEZ: Also last night, right alongside the party's most liberal leaders like Senator Bernie Sanders were Republicans who say they have had enough of Trump and planned a vote for Harris, including Mesa, Arizona, Mayor John Giles.

JOHN GILES (R), Mayor of Mesa, Arizona: I'm a lifelong Republican.

So I feel a little out of place tonight.

But I feel more at home here than in today's Republican Party.

John McCain's Republican Party is gone and we don't owe what a damn thing to what's been left behind.

LAURA BARRON-LOPEZ: Even former Trump Press Secretary Stephanie Grisham spoke out against her former boss.

STEPHANIE GRISHAM, Former White House Press Secretary: Behind closed doors, Trump mocks his supporters.

He calls them basement dwellers.

On a hospital visit one time, when people were dying in the ICU, he was mad that the cameras were not watching him.

LAURA BARRON-LOPEZ: As for Trump, he held his first outdoor event since his assassination attempt, a campaign stop alongside his running mate, J.D.

Vance, that was pegged as one on national security in Asheboro, North Carolina, but again heavily featured insults against the vice president.

DONALD TRUMP, Former President of the United States (R) and Current U.S. Presidential Candidate: She's a radical left believer.

She ruined San Francisco.

She ruined California.

And if she gets in, our country doesn't have a chance.

This calamity is on comrade Kamala Harris' shoulders.

LAURA BARRON-LOPEZ: Back in Chicago, the center stage tonight belongs to vice presidential nominee Tim Walz, who many voters still know very little about.