As James Joyner posts today a recent Strange Maps entry has produced a bit of buzz by showing the overlap between cotton production in 1860 and Democratic voting in 2008. Of course, a map of cotton production in 1860 and Democratic voting in 1908 would also look very similar, but for very different reasons, as Key points out in Southern Politics in State and Nation:

In its grand outlines the politics of the South revolves around the position of the Negro. Whatever phase of the southern political process one seeks to understand, sooner or later the trail of inquiry leads to the Negro.

For those not familiar with Key’s argument, he essentially argued that understanding the politics of the south (at least through the late 1940s, the time Southern Politics was written) required an understanding of how the political structures of the cotton belt states were designed to reinforce the supremacy of “black-belt whites,” the plantation owners who would have been outnumbered politically if blacks had a meaningful right to vote. Democratic single-party rule in the south, and the Democrats’ fortunes nationally, rested on this core of rabid support which saw Republican rule in the south or federal interference as nothing less than an existential threat. Obviously things have changed a great deal due to generational replacement and the changes wrought by the Civil Rights Movement, but it remains an interesting correlation as James points out.

Meanwhile, Kevin Drum argues that the South has lost influence in Washington due to the return of unified government under the Democrats, although a look at the chamber median (I haven’t run CJR on the latest House data, but I assume the results are likely to be similar) suggests that the “Blue Dogs,” most of whom are moderate-to-conservative southern Democrats, will have far more influence over what passes and fails in the 111th Congress than Drum might like.

Also of potential interest, Andrew Gelman looks at the relationship between county-level returns and race in various regions of the country.

Incidentally, I usually juxtapose two similar maps (one from Key, one from Gavin Wright’s work on southern economic history) in my Southern politics course—although I’m damned if I know when I’ll ever get the opportunity to teach it again, which is one of the drawbacks of teaching outside the “real” South.