I heard that Bush's handlers have been keeping him up late - they don't want him to look or sound "sleepy" during the debate. His bedtime is usually 9:00, you know...
But, to apply what we know about human circadian rhythms, keeping him up late will not do the thing. Sleep-time has a tiny if any effect on shifting the biological clock.
If Bush is a "lark", as I think he is from reports that he goes to bed early and gets up early, he will be sleepy at 9pm. Keeping him up late will just make him tired and cranky.
In order to have him be fresh, they have to keep him in a room with the light/dark cycle shifted a couple of hours later than the outside world for at least several days. They also need to shift the light cycle gradually. If the shift is sudden, he will suffer jet-lag.
I hope that Kerry is an "owl" - at his best at 9pm! He seems to fit the profile well, but I wonder if anyone knows his actual bedtime/wakeup routine.