I think one has to be very careful with taking the narrative of lower class, "hillbilly" republicans too much at face value. While yes, these people definitely do exist, the perception that this group is representative of republicans is something that is deliberately cultivated for political means.

As examples like recent protests show, the true core are people like business owners and wealthy suburbanites who are very much voting for their interests, not against them. This is also shown by how in every presidential election since at least 2012, voters below $50k always voted firmly in favor of democrats while voters above $100k voted firmly in favor of Republicans.