I cannot help but think of Richard Nixon's Southern Strategy, and how its legacy still poisons our politics. For a very long time, the deep cultural divide in this country was in part managed by the Democratic party. Its alliance of Southern conservatives and Northeastern liberals - perhaps exemplified by the Kennedy-Johnson ticket - gave what we now call parts of red and blue America a joint incentive to work out their differences through a common partisan affiliation. The had a fellowship that facilitated compromise. A less coherent ideological party structure actually created a more coherent political debate. I wonder if civil rights legislation would ever have been achieved without this...we should take a moment to remember Nixon. And the deep damage his opportunism wrought.Electorally, the "Southern Strategy" is pretty severely overrated. Look at the maps. The last year the South was solid was 1944; the last year that the South was solid while the Democrats lost was 1924. An interesting comparison is 1952 to 1920. Harding won overall by a much larger margin than Ike (Harding got 60%, Ike only 55%). And yet in the South, Eisenhower did better everywhere. He won Texas, Florida, and Virginia. In the deep South, check out Mississippi: Ike lost by a substantial 20 point margin, but Cox won Mississippi by 60 points in 1920 (by the way, I'm using this site for all of these numbers). And then, of course, five of the six states that Lyndon Johnson lost in 1964 were in the deep South.
So by the time Nixon is the nominee in 1968, the idea of a Democratic Solid South is an anachronism. Did Nixon accelerate the trend? I don't think so, really. It's really a done deal by 1964, at the presidential level.
That doesn't mean that there was nothing to the Southern Strategy in terms of Republican policy choices and rhetorical strategies. It was likely that as conservatives in the South moved from the Democratic Party to the Republicans (which, again, was going to happen regardless of any "strategy") that the conservative wing of the GOP would become a solid majority within the party, and that there would be no more presidential nominations for the moderate/liberal Eastern Establishment. On the other hand, it's at least possible that there were other potential paths for that conservative party majority on issues including race. So Sullivan's point might be relevant. I'm not sure. But I do think that as an electoral strategy, the Southern Strategy is pretty much a nothing.