Six Democratic White House contenders have so far qualified to appear on stage: Vice President Joe Biden; Sens. Elizabeth Warren of Massachusetts, Bernie Sanders of Vermont, Kamala Harris of California, Amy Klobuchar of Minnesota; and Mayor Pete Buttigieg of South Bend, Ind.
To participate, candidates must either receive at least 4 percent support in four qualifying polls of primary voters nationally or in early-voting states (Iowa, New Hampshire, Nevada or South Carolina); or they must receive at least 6 percent support in two qualifying early-state polls.
Candidates must also amass donations from at least 200,000 unique donors, with a minimum of 800 donors in 20 states, territories or Washington, D.C.
The December debate will be the sixth such televised forum of the primary cycle, and will follow a debate in the Atlanta area on Nov. 20 co-hosted by MSNBC and The Washington Post. Ten candidates have so far qualified for that debate.