Ancient geology and modern election results

Today I was delighted to read an account of the Driftless Area, and its effects on election results (HT: Kids Prefer Cheese).

The Driftless Area is a region, mostly in Wisconsin, but also covering parts of Minnesota and Iowa, that escaped glaciation during the last ice age (and thus lacks deposits of glacial drift, hence the name--it still snows a lot there). As a result, its topography is both hillier and more deeply dissected by river valleys than surrounding areas.

It also went for Obama significantly more than neighboring, equally rural areas did. While rural areas across the country (with another exception I'll mention below) went for Romney, these counties went blue. The demographics of the region don't seem to vary much from neighboring areas. What gives?

Maybe some ancient evil that was not extirpated by the busy glaciers...August Derleth could have explained it. And I looked--Sauk City, where he grew up, is right on the edge of the Driftless Area. Coincidence? I don't think so!

I was delighted, because I remember reading the only literary reference to the Driftless Area that I can remember: in #11 of the Man From U.N.C.L.E. books, The Invisibility Affair, by "Thomas Stratton" (a nom d'oncle of Buck Coulson and Gene DeWeese). The book involves an invisible dirigible, the Horicon marsh, and a car trunk full of margarine, among other things. I have cited the book's analysis of laws against selling colored margarine in dairy-producing areas as an example of regulations that claim to protect the public but actually protect some specific interest group, and no, I have never checked whether what it said was true, why do you ask? Ilya Kuryakin would never lie to me. The action takes place in that region of Wisconsin. Unfortunately I got rid of those books years ago, so I can't check whether it is still any good.  I loved those books as a kid.  And look how edumacated they made me!

Oh, the other geological influence on election results? The location of a Cretaceous sea determined where chalk would be deposited, and thus where a band of rich and well-drained soils would appear across the American South and be particularly suitable for large-scale cotton plantations worked by slaves, and thus where, to this day, large numbers of African Americans live, and vote Democrat, turning those counties blue.

Cretaceous seas and missing glaciers: anyone know of any other geological correlations to political alignments?