couldn't match obama's power. in bucks county, pennsylvania, didn't even win the state. so crowd size alone is not sufficient to win the white house. is it nevertheless a good yard stick? joining me now to discuss is douglas brinkley, a presidential historian, professor of history at rice university, author most recently of "american moonshot: john f. kennedy and the great space race." douglas, put this all in some historical context? >> well, at the beginning of the 20th century, william mckinley who was a two-term president he had what he called his front porch campaign. he would just sit in canton, ohio, and let people come to him and he would be like an oracle in his own backyard. but theodore vos svelte believed that crowd size mattered he would try to get 50,000, 60,000 wherever he went. i think crowds are important. it's called the enthusiasm