. >> senator sandersled president obama failed the presidential leadership test. >> madam secretary, that is a low blow. last i heard a unit states senator has the right to disagree with the president including a president who has done such an extraordinary job. >> clinton is trying to regain momentum in the race after her land slide loss to sanders in the new hampshire primary. the republican white house candidates are in south carolina ahead of next week's primary. they're gearing up for a debate tomorrow night and right now polling shows donald trump with a sizeable lead in south carolina. the next round of voting comes one week tomorrow in south carolina for the republicans and nevada for the democrats. >> thanks. ahead in our next half hour donald trump questions the pope. here why. as the candidates continue to battle it out you can take an interactive trip along the road to the white house. a new exhibit opens today at the constitution center. we're live with a sneak peak there. matt. >> reporter: this is a great opportunity for you folks at home because are the medicina parte