They’re being left behind by their own choices, in many cases. Many rural whites believe they have a right to stay exactly where they are, and do the same things their parents did, and enjoy all the things their parents had plus the benefits of modern society. In other words — if daddy was a coal miner, I should be able to be a coal miner too, and have all the stuff daddy did, plus an iPhone. They’re not being only left behind — they’re staying behind, and then complaining about it rather than adapting.
In a wildly ironic twist…the, GOP candidate for my House Rep was a friend of mine in college. He was certainly conservative (not inherently a bad thing) but he was smart, independent-minded, and self-assured. He continued to exhibit these traits after college. But his ENTIRE campaign is basically just “I’ll do what Trump says, and the Democratic incumbent won’t.” It’s genuinely sad.