"There's four kinds of folks in the world. There's the ordinary kind, like us and the neighbours, there's the kind like the Cunningham's out in the woods, the kind like the Ewell's down at the dump, and the Negroes."

Question

what rhetorical device or fallacy is this?

Answer 1

I don't know which rhetorical devices or fallacies you've studied, but this is an example of over-simplification.