Daniel Henninger wrote a column in the Wall Street Journal titled
Is John McCain Stupid? This, from a guy who is generally acknowledged as a conservative (Henninger, that is, I won't try and label McCain's viewpoints).
Henninger details McCain's contradictory statements on payroll taxes, and goes on to say that those statements could indicate that McCain isn't smart enough and does not understand the issues.
At this rate, Obama doesn't have to do anything to win, he just has to not screw up as much as McCain.