New York (CNN Business) More than 15 million viewers tuned in for part one of the 2020 presidential election's first primary debate on television Wednesday night.

The Nielsen ratings reflect enormous interest in the presidential race -- with millions of people tuning into NBC, MSNBC and Telemundo to size up the candidates who want to beat President Trump next year.

And these ratings don't even include streaming viewership on YouTube, Twitter and other sites.

The 15.3 million total from Nielsen combines the viewership on the NBC broadcast network, MSNBC, and the NBC-owned Telemundo network, which carried the debate in Spanish.

This trifecta of TV viewing options, plus intense interest in the Democratic primary, nearly set a new ratings record for Democratic party primary debates.

Read More