United in division? Primary race unraveling both political parties
Both Democrats and Republicans have big showdowns Saturday. On the Democratic side, Hillary Clinton and Bernie Sanders face off in the Nevada caucuses. Meanwhile, Republican presidential candidates are in South Carolina hoping to get enough votes to win the second primary of the year. CBS News contributor and former "Face the Nation" moderator Bob Schieffer joins "CBS This Morning" to discuss how the closeness of the nomination races is revealing the divide within political parties.