My 2 cents:

I grew up in SWPA, & there were quite a few coal miners in my family.

Coal is all these people know. They don't want retraining. They want to be well compensated for doing a filthy, dangerous job. They don't want to hear that their way of life--a high school education followed by a career mining coal--is gone forever. They would rather cling to the past than try for a better future. They're in denial that natural gas and automation took their jobs. Trump saw that, & exploited it. He told them exactly what they wanted to hear. He won't be able to deliver what they want. Then the real shitstorm will begin.