If the financial crash had happened six months later, Obama would have gotten more of the blame. Instead he was able to blame Bush.
If Hurricane Sandy had hit a week later then Obama's approval ratings would probably still have been below 50% on election day.
Who knows what would have happened if the head of the CIA had resigned a week earlier? Or what will come of his testimony this week (assuming that he still gives it)?
Obama spent weeks running on a "Save Big Bird" platform. What would have happened to this and the Million Muppet March if it had come out the the man who controls Elmo has been accused of having relationship with a 16-year-old boy?