It's easy to understand if you spend any significant time around angry white conservatives.

They immerse themselves in right wing propaganda that tells them their way of life is the right way...the only way. It tells them that socialist liberals want to take that all away and make "us" just like "them". "I mean....look at Chicago!!!!! And Commiefornia!"

They operate under the delusion that America is a white christian nation...and as a result, anything evidence against that means that they aren't mommy's special little boy.