Trump-Harris debate updates: Candidates go on attack in zinger-filled showdown

Lara Trump, co-chair of the Republican National Committee, said on CNN on Tuesday morning that Donald Trump has done "traditional debate prep," in addition to preparing by speaking to the media and attending public events.

"He has been preparing for this debate. He's done traditional debate prep," she said, before citing media appearances such as town halls, press conferences, podcasts and interviews.

The Trump campaign has previously focused on media and public events as Trump's debate prep, barely discussing more "traditional" debate prep.

Lara Trump framed her father-in-law's public events and media availability as a "stark contrast, of course, to what we've seen from Kamala Harris."

"I think Donald Trump is very focused on this debate tonight. He knows how important it is. He doesn't take anything for granted," she said.

– ABC News' Oren Oppenheim

Looking ahead to Tuesday night's debate, Vice President Kamala Harris tweeted "America, see you tonight."

Before departing for Philadelphia on Monday, Harris told reporters that she's feeling "good." She also gave a thumbs up.

The vice president's tweet also included a link to a list of debate watch parties the campaign is hosting across the country.

-ABC News' Fritz Farrow

Vice President Kamala Harris repurposed former President Barack Obama's suggestive dig at Trump over what Obama called his "weird obsession with crowd sizes" while speaking at the Democratic National Convention last month.

"Here's a 78-year-old billionaire who has not stopped whining about his problems …" Obama said in the clip used in the ad, just before a clip of Trump at rally plays.

"Ooh, she had a big crowd! Ooh, that crowd," Trump said in the snippet, mocking news reports about turnout for Harris.

"This weird obsession with crowd sizes... it just goes on, and on, and on," Obama says as the ad returns to him, followed by shots of small Trump crowds and sounds of crickets chirping.

"America's ready for a new chapter. We are ready for a President Kamala Harris," Obama says.

The Harris campaign said the ad, titled "Crowd Size," will air on Fox News the day of the debate because "Trump is known to watch" the network.

The 30-second ad is set to air nationally on cable news and in local West Palm Beach and Philadelphia markets.

– ABC News' Fritz Farrow, Gabriella Abdul-Hakim, and Will McDuffie

Anthony Scaramucci and Olivia Troye, former Trump administration officials, will serve as Kamala Harris surrogates in Philadelphia today, the Harris campaign announced.

"Listen, don't take it from us: Take it from the ones who know Donald Trump the best and who are telling the American people exactly how unfit Trump is to serve as president," Harris spokesman Michael Tyler said.

Scaramucci served as Trump's White House communications director. Troye served as the Homeland Security adviser to Vice President Mike Pence, as well as a top aide on the Trump White House coronavirus task force.

According to the campaign, they plan to discuss their support of Harris ahead of tonight's debate.

They are among numerous former Trump staffers who continue to speak out.

– ABC News' Will McDuffie, Fritz Farrow, and Gabriella Abdul-Hakim