The fourth round of Democratic debates will be held on Oct. 15 in Westerville, Ohio, with 12 candidates onstage, making it the biggest single-night debate to date.

How it works: This debate had the same requirements as September's. Qualifying candidates must have reached 2% in 4 DNC-approved polls and drawn 130,000 unique donors — including 400 donors in 20 different states. Oct. 1 was the final day to make the cut.

Why it matters: The Democrats' massive 2020 field has put pressure on the DNC to focus its primary on those who can really challenge President Trump.

Which candidates will be on stage:

Candidates that had at least 130,000 donors but did not meet the polling threshold:

Candidates who did not meet any qualifications for Ohio:

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Editor's note: This piece has been updated to reflect recent DNC requirement changes for the October debate.