Next Democratic Debate: The Top Four vs. Everyone Else. Presidential Election of 2020, Democratic Party, Debates (Political), Warren, Elizabeth, Biden, Joseph R Jr, Sanders, Bernard, Buttigieg, Pete (1982- ), Booker, Cory A, Klobuchar, Amy, Yang, Andrew (1975- ), Steyer, Thomas F, Gabbard, Tulsi (1981- ), Harris, Kamala D