The June 27 Democratic debate averaged 18.1 million total viewers across NBC, MSNBC and Telemundo, according to Nielsen, better than the 15.3 million who watched June 26. Among the 18.1 million, there were 5.3 million viewers 25-54 and 4.4 million in the 18-49 demo.
The live stream saw 9 million viewers and 14 million video views across all platforms June 27.
The debate ran from 9 to 11 p.m. ET both nights.
June 26 featured Cory Booker, Elizabeth Warren, Beto O’Rourke, Amy Klobuchar, Julian Castro, Jay Inslee, Tulsi Gabbard, Tim Ryan, Bill de Blasio and John Delaney.
On June 27, it was Marianne Williamson, John Hickenlooper, Andrew Yang, Pete Buttigieg, Joe Biden, Bernie Sanders, Kamala Harris, Michael Bennet, Kirsten Gillibrand and Eric Swalwell.
NBC News said the June 27 event was the highest-rated Democratic presidential primary debate, surpassing one in October 2015 by 2.6 million total viewers and 378,000 in the 25-54 demo.
The moderators were NBC Nightly News anchor Lester Holt, Today co-host Savannah Guthrie, Noticias Telemundo anchor Jose Diaz-Balart, NBC News political director Chuck Todd and The Rachel Maddow Show host Rachel Maddow.