The trend you described has been going on since Reagan, and the "rural poor" haven't budged. I have no expectation that attitudes will change in Rural America, not matter how bad things get.
It turns out when the other party runs on “we’re smarter and have better ideas than you and 25% of you are deplorable”, that people tend to increase their support for their current party rather than deciding “you know what? They’re right; we should switch to follow those coastal elites…”
Way longer than that if you want to get technical: https://en.wikipedia.org/wiki/Divide_and_conquer
In a nutshell that's why the South is so poor. They've been falling for this for generations.