The first night of the Democratic presidential debates drew an estimated 10 million viewers on NBC, according to early numbers first reported by The Hollywood Reporter.
The numbers are based on returns in roughly one-quarter of local Nielsen Media Research markets.
Final ratings on the debate will be available Thursday afternoon.
The 10 million viewership number only pertains to NBC. MSNBC and Telemundo also simulcasted the debate. Those numbers are also expected Thursday afternoon from Nielsen.
For context, the first Republican debate of the 2016 presidential primary season on Fox News, which featured then-real estate mogul as a front-runner in his first political debate, drew more than 24 million viewers in August 2015.
On the Democratic side in 2015, CNN drew 15.3 million viewers for a debate headlined by former Secretary of State , Sen. (I-Vt.) and three other candidates.
In 2011, the ratings were substantially lower.
For the first GOP primary debate in May 2011, just 3.53 million viewers tuned in to Fox News to see , , and battle it out in the first round of the fight for the party’s nomination.
In 2007, the numbers were even lower, with MSNBC drawing just 2.26 million viewers for the first Democratic debate in April 2007.
On the Republican side, only 2.19 million tuned in to ABC for the first GOP debate in August 2007.
The second night of the Democratic debate is slated for Thursday. It will feature former Vice President and other top-tier candidates including Sanders, South Bend, Ind., Mayor (D) and Sen. (D-Calif.), along with six other hopefuls.