I originally developed this as a comment to this post but wanted to expand its audience by one or two readers (no offense John C!).
We have been so conditioned to think that Republicans have a lock on brilliant politics that we excuse most anything that happens in the McCain campaign. What is becoming increasingly clear is that the wheels are off this particular bus and there is no grand sinister plan a la Karl Rove. All Obama has to do is remember what Napoleon said about not getting in the way while your enemy is making a mistake. Napoleon was not specific about what to do when your enemy refuses to stop making mistakes, however.
The narrative is increasingly about the McCain campaign tactics as it lurches about like an off-duty Navy pilot in a Florida strip club at 3AM (no idea where I got that from). Even the most sycophantic MSM types are being forced to note this.
This may actually be all the McCain campaign has to offer: a series of "unforced errors" followed by dueling "I meant to do that" and "Obviously I didn't mean that exactly" from various campaign representatives, while the principals attempt to avoid what should be a day (actually two days) of reckoning by attempting to push one debate to the date currently occupied by the other debate. Subtle.