There’s a branch of antisemitism which holds that Ashkenazic (i.e. European) Jews were not originally Jews but descendants of Turkic Khazars who converted to Judaism. This is used to delegitimize Israel by suggesting that today’s Fakestinians are the original inhabitants & that modern Israelis are interlopers.
These black thugs use fake Jewishness as an excuse to murder Jews. Bottom line.
I have run into those idiots here in Texas; they started telling me their nonsense about European Jews not being “real Jews” and just ignored it.
Bit of trivia, but examinations of the remains of ancient Judean burials showed Jews were swarthy, but white, and one had red hair:
Of course, King David had red hair (as did Ramses II; source in link above).