The feisty second round of the first debate with the 2020 Democratic presidential candidates on Thursday attracted 18.1 million viewers, making it the largest audience ever for such an event.

Nielsen data showed viewership for the Democratic candidates’ Thursday lineup, which included front-runners former Vice President Joe Biden and Sens. Bernie Sanders of Vermont and Kamala Harris of California, was up 18% over Wednesday’s face-off, which pulled in 15.3 million viewers. Both two-hour debates were simulcast on the NBC broadcast network, cable news channel MSNBC and the Spanish-language network Telemundo.

The previous high for a Democratic primary debate was 15.4 million viewers who watched the 2016 Democratic contenders meet on CNN on Oct. 13, 2015. The record for a Republican debate is 24 million viewers, for the Aug. 2, 2015, event shown on Fox News Channel, the largest audience for a non-sports cable program.

The higher ratings reflected the fact that the second-round matchup was largely seen as the main event of the two-night debate as Biden, Sanders, Harris and South Bend, Ind., Mayor Pete Buttigieg battled it out on the stage.


Nearly every TV political analyst said Harris — who took on Biden over his recent comments about being able to work with segregationists in the U.S. Senate — delivered the strongest performance.

The strong numbers for both nights of the NBC event is evidence that viewers are intensely interested in who the Democrats will choose to face President Trump in the 2020 race for the White House.

Trump drove news audience levels to record heights during the 2016 campaign and in his first year in office.

Previous primary debates rarely topped 10 million viewers. But analysts have said the public’s engagement in politics has reached stratospheric levels in recent years as polarization over Trump and his policies and personal style have intensified.


CNN will carry the next scheduled Democratic debate on July 30 and 31 in Detroit. ABC and Univision will carry the third matchup on Sept. 12 and 13.