Dan notes that Obama is planning to campaign a lot out West, perhaps hoping to exploit the spoiling power of the Barr-Root juggernaut, but it’s worth bearing in mind what Ambinder says on this point:

But the truth is the ONLY way, given the electoral college map that Obama is presented with, he can win the presidency if he loses Ohio or Pennsylvania by winning the West — by winning at least four of these states: New Mexico, Colorado, Oregon, Nevada and Washington. He cannot afford NOT to fight for the West. If he doesn’t fight for the West, he loses.

That’s very much in line with what I was saying earlier this month.