It goes back, I don't know, 30 years? With both agricultural US and union areas (sometimes the same places) the Democratic party consistently expected those votes without actually delivering anything. Bill Clinton and the party get blamed for things like NAFTA and jobs moving to other countries, etc. So eventually these folks drift to the Republican party. Many of these people were broadly conservative anyways. Later, the religious aspects and toxicity of what started with Newt manifested to what we see now.
I don't know if an evangelical Democrat would fly now. It's a really bad situation with very entrenched beliefs.
Maybe I missed it, but I didn't see in the article the reason why the stockpile I'd being sold. This I want to know.