I've been saying for some time that there's no way that Obama will win the White House. In fact, I think he's likely to lose by the largest margin since George McGovern.
There are many reasons for this, but the primary one is that Obama simply cannot live up to the Messianic image that he created for himself. The more time that passes, the more people learn that Obama is just another politician and, as far as politicians go, McCain is clearly superior.
A Messiah's followers are always disappointed. I don't expect things to be any different in Obama's case.