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

Harris' campaign said it's hosting more than 1,300 debate watch parties across the country, and running mate Gov. Tim Walz will deliver remarks at one of them in Phoenix Tuesday night.

The watch parties will be in all 50 states, with more than 100 planned on college campuses, according to the campaign. The events will be used for volunteers to make calls to battleground-state voters and share debate content on digital platforms.

More than 300 of the planned watch parties will be group specific, including Republicans for Harris-Walz and Veterans for Harris-Walz events in Arizona, North Carolina and Georgia. There will also be Latino house parties in Arizona and labor-organized events in Pennsylvania, according to the campaign.

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

Tuesday night's highly anticipated presidential debate will take place at the National Constitution Center, just steps away from where the U.S. Constitution was drafted and signed in Philadelphia in 1787.

The center is a private, nonprofit organization that attracts people from all over the country and world to learn about, debate and celebrate the historic document, according to its website.

Ahead of the debate, the stage where Harris and Trump will spar was photographed with the opening words to the constitution's preamble brightly on it: “We the People.”

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