On the evening of July 18, CNN announced the results of its random selection of Democratic presidential candidates. See this story, which lists who will debate on July 30, and who will debate on July 31.
Each night will have ten debaters. July 30: Bennet, Biden, Booker, Castro, de Blasio, Gabbard, Gillibrand, Harris, Inslee, and Yang.
July 31: Bullock, Bittigieg, Delaney, Hickenlooper, Klobuchar, O’Rourke, Ryan, Sanders, Warren, and Williamson.