Six years later and it's brought up from the dead?
But seriously after the results from 2012 and 2016 it does seem that AR and TN were really just waiting on a long term R trend. I mean both states have sizable Black populations, but there looks like a lot of poor White Democrats became increasingly dissatisfied and it prevented a swing towards Obama that could've happened in 2008 or 2012 (to a much lesser extent however) and it accelerated in 2016.
West Virginia is the most clear.
Ironically, even Arkansas swung against Hillary.
The current political system will climax when AR, TN, KY, WV, etc. have a similar percentage of Whites voting GOP as MS, AL, LA, etc.