Sorry about the link, I've uploaded the image to a separate hosting service here. A fun comparison is made with this similarly sized map of 2008 county election results. Taking a look at the ethnic geography maps provided here, shows that although Congregationalists may be a tiny fraction of present day county inhabitants, the effect of their past influence is still very significant.

Razib, 
 
[no linking to white supremacist websites please], and then compare it to the maps included in your post on "Where the whiter folk are." The correspondence between the maps would seem to lend support to Mencius' theory that SWPLism is the product of the degeneration of the Calvinist Christian culture that originally formed the backbone of the Yankee folkway.