Yeah, a joke that revolved around what a bunch of dumb hillbillies all us Trump supporters are. Can't even find Ukraine on a map if it had a picture of a crane on it, ha, ha, ha.
I find it incredibly funny when a British guy tells a joke in an American accent. Even though I am often being insulted in the joke, as a dumb American, I still find it hilarious. The worse the American accent, the funnier it is!
Similarly, having these guys do bad imitations of normal Americans was funny to me. The humor comes from the fact that they were so far off the mark.
I dunno. Humor is subjective. YMMV.