Why is Obama so vapid, hesitant, and gutless?: "...what I suspect in his case is that he had no idea of winning this time around. He was running in Iowa and New Hampshire to seed the ground for 2012, not 2008, and then the enthusiasm of his supporters (and the weird coincidence of a strong John Edwards showing in Iowa) put him at the front of the pack. Yet, having suddenly got the leadership position, he hadn't the faintest idea what to do with it or what to do about it."
I do get the feeling that Obama has been borne by momentum that he hadn't anticipated. Frankly, I don't think anyone in the field thought he would get this far or even that he had paid enough dues to be where he is today.