Time and again Wednesday, Obama went out of his way to find a center-right watch word or phrase (tax cuts, life, responsibility, charter schools, tort reform) to defend himself or make a point. McCain spent a lot of time talking to his current supporters, I didn't hear him making a move to the middle on many issues. It's as if both candidates were trying to win Indiana or West Virginia tonight, that's not good for McCain.
And the tax conversation may be one of the bigger misreads of this debate season. Taxes and spending are way down the list of issue importance in current polls. Sure, McCain's on the right side of the issue, it's just not a priority with voters right now and I think some may struggle connecting taxes to the current economic problems, particularly since taxes are relatively low.
As for the big pic, it's hard to see how this debate changed the trajectory of this race. It's now clear, for posterity, that Obama won the debate season. McCain won the convention season and that got him in the game, but the combination of the massive economic downturn with the debates has put McCain in as deep of a hole as any nominee has been this late in the process since Bob Dole. The map continues to look more favorable to Obama than McCain. But it's now in the hands of the voters. There's not much more information left to learn.