Even if you don't agree with their side of politics, you gotta feel bad for anyone that has to deal with the schedule of a campaigning politician.
I don't know why Obama would put himself through another 4 years of hell. (Just kidding. He obviously must like it. That or he is willing to go through all that to make America better. So either masochist or saint? Probably the second, though the first may be a bit more interesting )