I think this guy is pretty much on-target, but he fails to note a number of variables:
1) A new October surprise. Some would say that the opponents have nothing new to offer there. But that doesn't prevent them from making stuff up, and their willing accomplices in the media would still run with it.
2) A major attack in Iraq that kills a hundred or more troops. While in the grand scheme of things, this should not be important, if it happened close to the election, it would have a big impact. (Note that attacks here in the US would probably work in Bush's favor, not against him. If the terrorists have any brains, they'll know that. Evidence on whether they have any brains is mixed.)
3) There's a very small possibility that Bush could do something in the debates that would turn the dynamic against him. In a fair campaign, it would be practically impossible for him to say anything that would do that much damage. But since the media is just looking for the opportunity to hang something on him, a comparitively small mistake could be blown way out of proportion.
4) Very low probability miscellanea - A Dick Cheney heart attack, for example.
So there's no reason to get complacent, and every reason not to. The down-ticket elections matter just as much, and lots of them are closer than the presidential election.
It worked for them in Spain. However, you're correct - Americans are not Spaniards.
Kill joy.