There is a new most-watched moment of the 2024 presidential campaign.
Tuesday’s televised clash between Vice President Kamala Harris and former President Donald J. Trump drew 67.1 million live viewers, according to Nielsen, outdrawing Mr. Trump’s debate in June with President Biden by 31 percent.
Mass cultural events are rare in a polarized, choose-your-own-news era, but presidential debates still have pull. And the Nielsen data did not include likely millions more who followed along on social media and a variety of websites and streaming platforms.
The debate, hosted by ABC News in Philadelphia, fell short of cultural touchstones like the “Seinfeld” finale in 1998 (76.3 million), but viewing habits have shifted since then. The TV audience for the Harris-Trump matchup was roughly comparable to Mr. Trump’s second debate with Hillary Clinton in 2016, and President Barack Obama’s first meeting with Mitt Romney in 2012.
Younger and early-middle-age viewers in particular helped drive up the television audience on Tuesday. Roughly 50 percent more adults between the ages of 18 and 54 watched Ms. Harris and Mr. Trump, compared with the June debate, according to Nielsen.
The big ratings winner of the evening was ABC News — about 19.1 million people watched on ABC alone. The debate was simulcast on more than a dozen channels, with Fox News drawing 9.1 million viewers, the largest audience of any cable network on Tuesday.
CNN, which hosted the June debate, had the lowest total viewership of the seven biggest networks, a reversal from June, when it had the highest.
Executives in the television industry had expected Tuesday’s debate to bring in higher viewership than the Biden-Trump meeting in June. That debate was held far earlier in the calendar than usual, when many Americans were away on vacation. Television use is also higher in the autumn than in the summertime.
The subsequent shake-up of the presidential race — with Mr. Biden dropping out and Ms. Harris taking his spot — has revived interest in the election. In particular, voters have said they are eager to learn more about Ms. Harris, with Election Day less than two months away.