Then why say "some Jews?" Why not just "some people?"
OK, that's a good point.
"Some American Jews" tells the truth about the very nature of this type of humour. Holocaust jokes about Jews were very popular not long time ago among some Poles. I never found them funny and expressed my dislike openly making some people's eyes go very big. Using expressions like "verimin" in relation to an ethnic group doesn't have anything to do with PC or satire.