Could 2020 Democratic nomination still be up for grabs come convention?

Wednesday’s fiery 2020 Democratic debate came at a critical moment in the campaign, right before the Nevada caucuses and with early voting underway in a dozen states. Judy Woodruff talks to ABC News’ Matt Dowd, former chief strategist for President George W. Bush’s reelection campaign, and Democratic campaign advisers Michael Meehan and Iam Sams about debate performance and the race’s unknowns.