Despite an underwhelming performance in yesterday's primary contests, Bernie Sanders says he remains a contender for the Democratic presidential nomination. Sanders pointed to Sunday's one-on-one debate with Biden in Arizona as a chance to change the minds of voters who say they like his policy ideas but view Biden as the best option to defeat Trump in November. This episode: White House correspondent Tamara Keith, political reporter Danielle Kurtzleben, and campaign correspondent Scott Detrow.