Why did New Hampshire, Vermont, Massachusettes, and Rhode Island go so strongly for McCain over W?
Papi Bush came off as very much a New Englander. He was the last "Red Tory" Republican, so to speak.
Dubya, on the other hand, was a straight-up Southerner (at least optically speaking). He adopted the drawl, the lifestyle, and the cultural values. His campaign was a mish-mash of the Reagan Realignment and the religious right's "moral values" crusades. Secular New Englanders don't take too kindly to that style of campaigning or policy.