Jim, it seems obvious that Nickolas is playing the self-fulfilling prophecy game — the same “inevitability” argument that Team Obama began using in the Democratic primaries in March. This is essentially what Nate Silver is doing, as well.
This manipulation of expectations will work only so long as Obama remains ahead in the polls. You saw the semi-panicked reaction last week, with the collapse of the bubble caused by Obama’s foreign trip. Should McCain ever move ahead in the polls and stay ahead for any length of time, all of Obama’s media buddies will start in on a “what went wrong” meme that could drag him down.