When it comes to chronicling the bumpkins of darkest Arkansas, New York Times magazine writer Monica Potts is working in a long tradition. Mark Twain got there first in “The Adventures of Huckleberry Finn.” His portrait of slack-jawed “Arkansaw lunkheads” watching dog fights in ramshackle riverside towns fixed the region’s image for more than a century.
H.L. Mencken’s influential 1917 essay, “The S…