Dems look for edge amid jam-packed presidential debate

This week the top 20 Democratic presidential candidates are facing off over two nights in Miami. It's the first official debate of the 2020 primary season. Special correspondent Jeff Greenfield talks with bipartisan strategists to learn what the candidates can do in such a big field, and joins Hari Sreenivasan to discuss whether a debate held months before the first votes can make a difference.