Matt's got an interesting post on the McGovern realignment, which basically argues that the actual realignment happened four years before, when Nixon and Wallace left Humphrey with a mere 42% of the vote. That it split three ways made it look more like an anomaly and less like a phase shift. But Nixon's landslide in 1972 came from getting the Wallace voters, and we wrongly ascribed that to McGovern's Vietnam position, rather than the logical extension of 1968.
That's correct, but only to a point. As a historical point, Matt's quite right. But insofar as it affects modern elections, the South is no longer, by and large, voting against us because they don't like black folks. What we're dealing with instead is party identification, law-and-order preferences, religious issues, and an aggressive military culture. Since Democrats aren't Republicans, are considered soft on crime, questioning towards authority, hostile to Christianity, uncomfortable with the armed forces, and condescending and hostile towards Southerners, we're facing a real cultural problem. In that way, as Jim Crow became less acceptable to a more modern South, these issues subtly replaced the racist appeal of the Republican party. The South subbed out the original reasons for their realignment and simultaneously got angry at Democrats for reminding them of their embarrassing past.
In this way, McGovern matters, and his failure should be taken seriously by Democrats. Everything McGovern represented -- disorder, the 1968 convention, peaceniks, hippies, etc -- has been reanimated into the Southern stereotype of the Democratic party. In some places, like Virginia, that can be overcome with the right candidate. In other parts of the region, we've got no chance. But even if realignment wasn't originally about these issues, for a fair percentage of contemporary Southerners, it now is, and that makes the difference academic.
Update: For a really interesting essay on the South's political evolution since realignment, check out "The Real Southern Problem" (pdf), by former Alabama Democratic Congressman Glen Bowder. I don't agree with him on everything, but he makes a hell of a case for why the Democratic party is losing there, how much of it is attitudinal and related to what he calls "guy culture", and why we can't give up on it.
