Run a pro-abortion or anti-2nd amendment Republican nominee and the voting map WILL change more than a lick and you'll see a Democrat win.
Bush won. He was never strongly anti abortion, other than in words. He spoke of a need to "change people's hearts," but never pushed an anti-abortion platform.
Rudy and McCain are basically the same. Both see it as mainly a state's issue. Both are willing to allow some abortions. Both are opposed to partial birth abortion except to save a mother's life. Both believe in fairly strong parental notification. I predict that neither will touch the "right third rail" of gun control.
I also believe that the number of far rightwingers who will sit on their hands on election day will be greatly outnumbered by the moderates who will vote for Rudy or McCain.