There’s also the factor of the death or at least severe weakening of regional cultures, think your old Californian desert, Appalachian, or Old Boston cultures. A lot of these were weakened or even wiped out by the Great depression, Dust Bowl, and post war migrations, meaning that even the stronger of these more regional cultures can barely flex even in their own areas.

While it’s obviously misguided there is a reason rural folks are so conservative, the source isn’t necessarily political it’s because they recognize that their culture is weakening to the mainstream Pan American culture but assume it’s political since they don’t really have the language to figure out otherwise.