Actually, since this happened in Georgia it's more of a reflection on Bush's popularity with "all those other people" than with his electorate, though I think Bob pretty much nailed it. Bush probably wouldn't have been possible 30 years ago, because at that time the Republican Party hadn't yet "discovered" how to mobilize the God, Guns, Glory crowd, and the Democrats weren't quite so ridiculously incompetent.
Though it's certainly ironic that someone flung a grenade at him in a country which was recently "liberated" with Washington's open support. Well, at least he still has...uh...Poland.