 There's been talk about whether he had a cold, but I think a lot of people who watch that debate don't think that that is enough of an explanation. And they want answers about whether he can do this job now, in addition to responding to those calls from members within his own party for him to potentially drop out of the race, no longer be the Democratic nominee. I think he needs to reassure Americans that he's up for being commander in chief right now this summer.