IA, CO, NM, and NV = 278 ECVs
Obama could also put Montana, Alaska, one or two of Nebraska's ECVs, and the Dakotas into play. If Obama selects Chuck Hagel as his running mate and if Bob Barr can reach into the high single digits in the plains states and the mountain west, Obama may pick up five ECVs in this nominally Republican part of the nation.
If you have to play
that sort of game then you've lost already. Maybe quite badly. And your attempts at that game will fail in such a way as to make you look rather stupid.