This has been getting some attention for several days now: a sort of cultural map of the U.S. based on the varying cultures of origin of current inhabitants. The first thing I noticed is that it conforms to what I was saying in a discussion with Art Deco a few weeks ago about the culture of the region including north Alabama and Tennessee.
In naming Vanderbilt as a university located in the Deep South, I asserted that if northern Alabama is in the Deep South, then so are the neighboring regions of Tennessee. Or, conversely, if those parts of Tennessee are not in the Deep South, then neither is the part of north Alabama where I grew up. As you can see, this map draws the line between Greater Appalachia and Deep South well south of the Alabama-Tennessee line. Call the regions what you will, there is a noticeable cultural similarity, at least in some classes, among people living in north Alabama and as far north as southern Indiana.

Any exercise of this sort can only be taken as an extreme generalization. Still, with that in mind, I think there's something to it.
The analyis, at least as represented in the accompanying article, is concerned only with regional differences in attitudes toward violence, and though the author seems to be trying for detachment is clearly written from a liberal point of view. It's pretty clear that the southern region is to be considered backward if not crazy.
One possible lesson that might be drawn from this is missed by the author, though he states the premise:
With such sharp regional differences, the idea that the United States would ever reach consensus on any issue having to do with violence seems far-fetched. The cultural gulf between Appalachia and Yankeedom, Deep South and New Netherland is simply too large.
The conclusion I would draw from that observation is that, given the deep differences among the regions, a great deal of latitude in ordering their own affairs ought to be accepted, and that an attempt to impose uniformity on the entire nation would a big mistake, and bound to cause more trouble than it prevents, not only in relation to the problem of violence but to many other disputes. Unfortunately that is not the conclusion the author draws, but rather:
The deadlock will persist until one of these camps modifies its message and policy platform to draw in the swing nations. Only then can that camp seize full control over the levers of federal power—the White House, the House, and a filibuster-proof Senate majority—to force its will on the opposing nations.
This is unwise. And, I might say, a characteristic northern mistake.