What's the similarity between a jew and a nazi? They both die if you gas them.
I'm not sure I get the joke?
I mean that the jews and the nazis are the same. They should be 'treated' in a similar fashion.
The joke's intent may have been to imply everyone's the same, which is a positive message. But it could also be taken to mean that "Jews are as bad as Nazis". Marginalizing an entire group like that is what caused Nazis and similar things to occur in history.