Final lineup set for sole night of ABC Democratic primary debate

The final lineup for the third Democratic debate is set for a single night in Houston in two weeks on Sept. 12.

Eight months into the campaign season, the third matchup in a series of Democratic National Committee-sanctioned primary debates will feature a winnowed field. It's the smallest qualifying roster yet for a debate with 20 candidates still in the running.

The 10 candidates certified by the Democratic National Committee to participate in the debate, hosted by ABC News in partnership with Univision, will appear on stage in the following order, from left to right:

The DNC formally notified the campaigns Thursday that their candidates had qualified for the debate. The podium order -- where the candidates will stand on the debate stage in relation to each other -- was determined by polling averages, based on the last 10 polls certified for qualification by the DNC with the highest polling candidates near the center.

The debate format will be one minute and 15 seconds for direct responses to questions and 45 seconds for responses and rebuttals. Candidates will have the opportunity to deliver opening statements, but there will be no closing statements.

As previously announced, ABC News Chief Anchor George Stephanopoulos, ABC News "World News Tonight" Anchor and Managing Editor David Muir, ABC News Correspondent Linsey Davis and Univision Anchor Jorge Ramos will moderate.

The debate will be held at Texas Southern University, a public, historically black university, and will air from 8 to 11 p.m. ET across ABC, Univision with a Spanish translation, locally on KTRK-TV and on ABC News Live. The streaming channel is available on the ABCNews.com, Good Morning America and FiveThirtyEight websites and mobile phone apps, as well as Hulu Live, The Roku Channel, Facebook Watch, AppleTV, Amazon Fire TV, YouTube, Apple News, and Twitter.

In the two prior debates in Miami and Detroit earlier this summer, the current two polling front-runners never tangled on the same stage. But in September, Biden and Warren are set to clash for the first time as the field enters a new phase of the primary.

The ideological divide within the Democratic Party will be front and center. Biden will be up against both progressive stalwarts Warren and Sanders, who have avoided criticizing each other so far this cycle, and who even teamed up to champion their shared vision for transformative progressive reform during the July debate.

But Warren might not have an ally this time to help play defense against an expected new round of criticism. After spending the first part of the year trailing Sanders, Warren often now outpaces her liberal colleague in recent polls.

Biden, with a target on his back, is expected to have to fend off attacks from all sides with Harris, Booker, Buttigieg and Yang all armed with fresh ammunition. Klobuchar is another middle-of-the-road candidate who might take aim at a progressive agenda that touts Medicare for All and free public college tuition.

Castro and O'Rourke, both appearing in their home state, are also on the same stage again, potentially teeing up another wrangle between the two Texans.

Earlier this year, prior to the first Democratic debates, the DNC announced more stringent qualifying rules for the fall debates in September and October. Details for the October debate have not yet been announced.

In order to qualify for the September debate, candidates needed to cross both the polling and grassroots funding thresholds. Candidates must have received 2% or more support in at least four national polls or polls conducted in the early-voting states of Iowa, New Hampshire, South Carolina and/or Nevada and have been publicly released between June 28 and August 28.

Any candidates' four qualifying polls must have been sponsored by one or more of the following organizations approved by the DNC: The Associated Press, ABC News, CBS News, CNN, the Des Moines Register, Fox News, Monmouth University, NBC News, The New York Times, National Public Radio, Quinnipiac University, University of New Hampshire, The Wall Street Journal, USA Today, the Washington Post and Winthrop University. They also needed to be conducted by different organizations or -- if by the same organization -- had to be in different geographical areas.

Candidates also needed to receive donations from at least 130,000 unique donors over the course of the election cycle, with a minimum of 400 unique donors per state in at least 20 states. Qualifying donations must have been received by 11:59 p.m. on Aug. 28 for the September debate.

HOW TO WATCH THE DEBATE: The ABC News Democratic Debate will air live nationally on the ABC Television Network and Univision (with a Spanish translation) and locally on KTRK-TV. ABC News will livestream the debate on ABC News Live – the network’s 24/7 breaking news and live events streaming channel – on Roku, Hulu, AppleTV, Amazon Fire TV, YouTube, Apple News, Facebook, Twitter, and the ABC News, Good Morning America and FiveThirtyEight websites and mobile phone apps. Univision News will also livestream the debate on all of its digital platforms including Facebook, YouTube and Periscope.