If McCain were to get the nomination, I believe his running mate will be former PA Gov. Tom Ridge.
That would be a smart move. Ridge is socially moderate, has executive experience and was relatively popular in Pennsylvania (I believe -- Correct me if I am wrong.)
That Ridge is another war hero, like McCain, might strike some as overkill. But in the long run, it's an asset.
Oh, one other possible benefit. Ridge is seen by some as yet another moderate cast out of the current administration. (I know, I know -- he wanted to spend more time with his family...) But Christine Whitman, Andy Card and Colin Powell all vacated. Ridge, another social liberal, did also.
Coincidence? Maybe.
But coincidence or not, Independent voters and moderate Republicans who might be inclined to vote Democrat in 2008 could see the inclusion of a moderate castoff from The Decider's administration as a plus.
The Ridge luster has worn off a bit for some of the peopel in this state, but I think that is largely due to Ed Rendell's efforts to rewrite history in order to blame his failures on the previous administration.
That being said, Ridge is still pretty popular he. He would certainly help McCain in the west, though I suspect McCain would be pretty popular here as is. Same with the Northeast.