I listened to a Barak Obama speech yesterday. If you haven't already done so, I'd recommend it.
He is harnessing the Democrat's fatigue with their party and the recognition of failure in their politics of hatred.
They're more easily had than we have realized.
I don't know of anyone, anywhere, off the top of my head who said McCain would take it. Remember that in mid December all the establishment pundits like Barnes and Kondracke were saying that only Romney and Giuliani had viable paths to the nomination.