Former U.S. Vice President Joe Biden, 2020 Democratic presidential candidate, speaks with patrons during a campaign stop in Eldridge, Iowa, U.S., on Wednesday, June 12, 2019. Biden expressed concern about the format of the first Democratic presidential debates, saying that having 20 candidates face off over two nights means there will be little depth to the events. Photographer: Daniel Acker/Bloomberg Photo: Daniel Acker / Bloomberg / © 2019 Bloomberg Finance LP