audience participation
opening and closing statements
split over two nights (early debates)
moderated questions
multi-candidate stage
reduced field in later debates
time-limited answers
Kamala Harris confronts Joe Biden on busing
Michael Bloomberg's first debate performance
Amy Klobuchar and Pete Buttigieg exchanges
Andrew Yang's universal basic income proposal
COVID-19 pandemic impacts final debate format
Joe Biden emerges as frontrunner
Tulsi Gabbard criticizes Kamala Harris
Elizabeth Warren and Bernie Sanders clash on gender