I have been worried about Ohio. I heard encouraging news earlier today. Then I heard similar news from separate source who does not know the first source. Then I read Jay Cost's thoughts, which are sound.
Let me add one more. If the President didn't think he had a shot at winning Ohio, he would not be wasting his time there. California still stings his memory. That he is going, but not frequently, does, as Jay suggests, indicate his campaign knows something we don't.
Also, Kerry has outsourced his door to door efforts. That will cause him problems.