The general election result obviously. 
Nah Chris you obviously forget to take the age wave into account. The age wave, as well as the growth of hispanic voters will make it impossible for any future Republican to ever win the White House ever again, EVER!
Not to mention the leak of the Batman/Robin gay sex scandal, would really hurt the ticket.
And even if Superman did win (which is impossible if you consider the age wave and his running mate's sex scandal) he couldn't become president, as he's not an American natural born citizen.
I will conclude then, that Superman (Giuliani) would have less than 1 % chance of winning, and in fact Obama would probably win in a Reagan landslide.
