A different lens to view this through has to do with economic and population shifts over the last century. Specifically the huge increase in agricultural productivity.

"In 1900, just under 40 percent of the total US population lived on farms, and 60 percent lived in rural areas. Today, the respective figures are only about 1 percent and 20 percent." [1]

That's a large erosion of political and economic power in those rural areas as more people moved out of agriculture into other industries that tend to be located in population centers. Not sure how that changes unless we move away from large corporate farms back to smaller family farms (See various Wendall Berry essays and novels where he lays out what's happened to rural areas over the last century as family farms have dwindled), however, that seems very unlikely.

[1] http://jaysonlusk.com/blog/2016/6/26/the-evolution-of-americ...