Presidential debate 2024 livestream: Trump, Harris face off on ABC News.

Vice President Kamala Harris and former President Donald Trump faced off for the first, and potentially only, time in 2024 in a high-stakes presidential debate hosted by ABC News. The debate took place at the historic National Constitution Center in Philadelphia. ABC World News Tonight anchor and managing editor David Muir and Linsey Davis, ABC News Live Prime anchor, moderated the 90-minute primetime debate with no studio audience.

The Harris and Trump campaigns agreed to ABC’s debate rules after weeks of back-and-forth wrangling over live microphones. The Harris campaign initially pushed for the microphones to be turned on the whole time. But the Trump campaign wanted them on only for the candidate whose turn it is to speak. Ultimately, both camps agreed to leave microphones on only for the candidate speaking, similar to the rules in the June 27 CNN debate between President Biden and Trump.

Trump won a coin flip toss that determined the order of closing statements. He chose to go last. The candidates did not give an opening statement and had to stand behind their respective podiums for the entire debate.

Tuesday night’s debate is the only presidential debate on the schedule. However, the vice presidential nominees, Democratic Minnesota Gov. Tim Walz and Republican Sen. JD Vance from Ohio, are set to face off on Oct. 1 in a debate hosted by CBS News.

An estimated 51.3 million people watched the Biden-Trump debate on June 27, with viewership falling significantly lower than their last debate in September 2020. That 2020 debate had 73 million viewers.

You can watch the Trump-Harris debate across ABC News’s properties, which include ABC News Live’s online streaming, Disney+ and Hulu.

Yahoo also features real-time coverage and analysis from our editorial team.

Tonight's debate went longer than planned. Tonight’s Harris-Trump debate was set to go 90 minutes. Trump and Biden’s debate in July hosted by CNN was also scheduled for 90 minutes, but ended up running about eight minutes long.