Jew-hating Jews.
It was ever thus.
Bernie is targeting the Satmar Jews — they are a fringe group of Hasidic Jews who oppose the existence of the modern state of Israel — for multiple reasons — it being pre-Mosiach, being a liberal (classically) Democracy, and because non-Jewish people (which they defined as basically everyone but them, but especially paternally “Jewish” persons) are welcome.
The fringe-of-this-fringe are the idiots you see meeting with mullahs in Iran.
Ironically, there are fair number of their theological cousins in Israel, who hate Israel, but really like our welfare benefits.
They are (generally) the idiots you read about acting like Muslims and throwing rocks at women for wearing short dresses.
Welfare mooches fit well in Bernie’s target demographic.