The ultra short list in brief:

1. He is black. Joe Biden had it right: "this is story book, man."

Americans desperately want to elect a black president. Colin Powell could have had it. Condi might have scored a double. But Obama got there before anyone else. White America is going to feel great relief when this barrier is broken. As we find out more about Obama, he is much less story book than originally advertised--but his early momentum carried him through his dismal final three months.

Looking Ahead: this basic collective truth remains his most powerful asset in the Fall.

2. He pandered to the nutroots on the war.

Hillary ran a Fall Election campaign, offering a sober foreign policy strategy. Obama appealed to his party's extreme left wing, anti-war base. Once she realized her giant problem, she tried to get left--but it was too late.

Looking Ahead: this necessary primary tactic should prove his greatest liability in the Fall.

3. He dominated the caucuses. Ironically, the formerly insignificant smattering of caucuses in formerly insignificant places taken as a whole became "King Caucus" and provided his winning margin. She expected a quick knockout and bet everything on Super Tuesday. In truth, she was actually much better on the traditionally much more conclusive big primaries in big states than he was (Florida, Pennsylvania, Ohio, Texas, etc.).

On the other hand, he bet on the caucus because he had no other choice. She bet on the primaries because it was the historically smarter strategy. Life is funny.

4. The mainstream media fell in love with him.

An Aside: Bill is exactly right about the pro-O bias (although he seems ignorant that the MSM devotion to his wife's opponent has been the status quo for every Republican candidate of the modern era).

Looking Ahead: needless to say, another huge advantage in the Fall.