While it is sort of hard (not impossible) to think of many other reasons to vote for Al Gore, John Kerry, and John McCain, obviously such a measure can only catch racist Democrats. Most other rural areas (excempting the Upper Midwest) already are Republican anyways.
Very true. Most of the areas that swung towards McCain contain groups that are subsets of culturally southern whites, but have a sizeable Democratic vote (e.g. Appalachia, Cajun Louisiana). The Deep South didn't swing much, because whites already vote overwhelmingly Republican. Democratic gains in FL, NC, and VA were in areas that were not culturally Southern (e.g. NoVa, Research Triangle NC, southern Fla.) and from higher black turnout.