text:  And there was a seminal moment. This was really the end of Walter Mondale's presidential campaign. Let's play cut number three, please. You already are the oldest president in history, and some of your staff say you were tired after your most recent encounter with Mr. Mondale. I recall yet that President Kennedy had to go for days on end with very little sleep during the Cuba Missile Crisis. Is there any doubt in your mind that you would be able to function in such circumstances?