Ezra Klein theorizes that the Obama camp may have had the concept for this add sitting around for months, just waiting for McCain to say "I'm not George Bush!" in a debate. As impressed as I've largely been with the Obama campaign's strategic maneuvers these past few months, I'm still not sure about that. They could have just got lucky and thrown this together. Wouldn't be that hard. Still, this may be the most effective anti-McCain ad I've seen: