Senate Democrats won back their majority last week, and now they’re fighting over who will lead it. Maryland Sen. Chris Van Hollen has thrown his hat in the ring and says he will take on current Democratic leader Chuck Schumer. Congressional correspondent Lisa Desjardins reports on the first serious challenge Schumer has faced to his party leadership. Amna Nawaz: Well, Senate Democrats won back the majority last week. Now they're fighting over who will lead it.