Maybe I am not being serious, but...

Old white men were the only demographic subset where McCain won.

This fact was predicted all through the campaign by every poll there was.

Although the Obama campaign officially didn't endorse to use that line, many well-meaning activists didn't forget to mention that Old White Men supported McCain.

People who for some reason tend to mistrust Old White Men might have been thus more inclined to vote for Obama.

But then, Old White Men knew all of this beforehand, and might have done everything precisely so that it looked like McCain was their choice and then many people stayed away from him.

Which still means a conspiracy of Old White Men put Obama in the presidency.