WESTERVILLE, Ohio — The Democratic debate stage is getting bigger, but television ratings are getting smaller.
The primary debate on Tuesday night in Ohio, co-sponsored by CNN and The New York Times, drew about 8.3 million live television viewers on CNN, Nielsen said on Wednesday. The event featured 12 candidates, up from the 10 who debated last month in Houston at an event seen by about 14 million people on ABC News and Univision.
Interest in the 2020 presidential race is clearly strong. The 8.3 million people who watched on Tuesday roughly equaled the number of viewers for a 2008 matchup between Barack Obama and Hillary Clinton, days before the so-called Super Tuesday primary night.
But the three-hour Ohio event — which featured a cavalcade of candidates attacking Senator Elizabeth Warren of Massachusetts — did not perform much better than this year’s lowest-rated primary debate, a CNN forum in late July in Detroit with 8.2 million viewers.
Some viewers may be growing tired of watching an oversize Democratic field. A dozen candidates qualified for Tuesday’s debate, based on criteria set by Democratic officials, who are keen to avoid any suggestion of skewing their party’s presidential contest.
This was also the first debate to be held since the start of the fall TV season, when viewers flock to new episodes of their favorite shows. Over all, the Ohio debate — which was also competing with Game 4 of the National League Championship Series — was the third-most-viewed program on television on Tuesday, behind episodes of “N.C.I.S.” and “F.B.I.” on CBS.
Online viewership is not included in Nielsen numbers, and many people most likely watched via Facebook and other streaming venues. CNN said that at any given minute of Tuesday’s debate, an average of 450,000 people were watching on CNN.com or nytimes.com.
Held in a converted gymnasium at Otterbein University in Ohio, the event featured the most candidates ever assembled on a primary debate stage. Producers faced a difficult task in choreographing the stage, but for the most part, the night went smoothly.
The moderating team — Erin Burnett and Anderson Cooper, of CNN, and a television newcomer, Marc Lacey, the national editor of The Times — kept outbursts and interruptions to a minimum. The journalists also stepped back at times to allow the candidates to engage one another directly. Organizers granted 75 seconds for each candidate to respond to questions, up from 60 seconds for the last round of CNN debates.
Candidates were at their lecterns for the 8 p.m. start time, and the questions began immediately. It was a more restrained approach than CNN’s debates in Detroit, which featured a singing of the national anthem in prime time and a Hollywood-style introductory video that some mocked as hyperbolic.
This was also the year’s first Democratic debate to start with questions about President Trump and his behavior in the White House. Earlier debates began with a detailed policy discussion about health care.
The next Democratic debate, on Nov. 20 in Georgia, will be broadcast on MSNBC, with The Washington Post as a co-sponsor.