What happened to Elizabeth Warren? Obama’s campaign manager weighs in

With Sen. Elizabeth Warren’s decision to end her White House bid, the battle to take on President Trump in November is now essentially a two-man race: former Vice President Joe Biden vs. Sen. Bernie Sanders. But whoever becomes the Democratic nominee, how can the party rally around him to unseat Trump? Judy Woodruff discusses with David Plouffe, campaign manager for former President Barack Obama.