To be clear, this is where the Bush II years spiel about "real Americans," which became even more prominent with the rise of Sarah Palin, was always going. This is the obvious end result of the "if you're not with us, you're with the terrorists" attitude of the Dubya administration.
This has been festering for decades. Trump is just a symptom. An old, moldy, filthy symptom of a violently dangerous disease.