Dickerson and Cordes on tightening Democratic race

The CBS News Battleground Tracker in Iowa finds the Democrats are in a much tighter race than the Republicans. Bernie Sanders leads Hillary Clinton by just one point, 47 to 46 percent. But in New Hampshire, the senator from neighboring Vermont holds a 19-point lead. Congressional correspondent Nancy Cordes and CBS News political director John Dickerson joins “CBS This Morning” to discuss the state of the Democratic race.