I spend a lot of time in the “flyover” areas, and this is simply not true at all. Maybe it was long ago, but we are no longer living in that age. It seems like the media want to portray middle America as some kind of medieval redneck nightmare thunderdome, for reasons I cannot fathom.
I'm not even sure it was ever true. I think it's just become part of the folklore of urban leftists, potentially as a way to justify their lives even when nobody was demanding a justification.