some are embarrassed that donald trump was preaching to this audience. we didn't feel that was the focus. he was repeatedly questioning president obama's birthplace. i can't imagine that we could go into the next presidential election still relit kating that pathetic fight. >> david gergen, you worked with a lot of presidents on all different sides of the aisle. is it responsibility of a leader to actually say something? >> it's the responsibility of a leader to push back against prejudice. that question with heavily laiden with prejudice. we've had two presidents, president bush after 9/11 and president obama to his credit have continue you'lly tried to help people understand that muslims are not a problem in america. there are some who are trying to bring terror. but he should have pushed back on that question. he should have made it very clear that he's proud to have the muz limgs in this country. they're great, many of them are great americans.