Kerry’s grandfather was a guy named Fritz Kohn from Prague. When he went to Boston, you could go much further with the last name Kerry than Kohn. So he changed it. Kohn’s son (John Kerry’s father) married very well; his wife was from the wealthy Boston Binghams and Forbes families. Yet John Kerry would go to the St. Patrick’s Day dinner and yell about “us Irish”. John Kerry is far less Irish than Kerry Gold Butter; just another indicator of what a phony the guy was, and is.
Yes, Kerry’s grandfather from Prague changed his name (it may have been Cohen instead of Kohn—at any rate Jewish, but Kerry’s maternal side wasn’t Jewish and he was raised as a Catholic). Supposedly his grandfather chose the name Kerry from looking at a map of Ireland (there is a County Kerry...in Ireland it is the butt of the Irish equivalent of Polish jokes).