play a clip of that ahead. the phrase that came to mind was a phrase he's used before to describe jeb bush, low energy. and i wonder if the rigors and demands of running for president, which seems grueling. i don't know, is the guy prepared for it? if he's going to have to keep doing this, can he do it? >> reporter: i don't know. i mean, he does have a unique advantage out there. he has his own jet. when he comes in to do these campaign stops, he's not driving in a bus from place to place, either taking a helicopter or limousine. he's flying home every night and sleeping in his bed every night. that adds to his ability to stay out in the field. the other candidates are taking commercial flights. slogging through airports. i'm slogging through airports to keep up with them. it's an exhausting endeavor, and i'm a good 30 years younger than he is. will he be able to maintain