Leftist anti-Semitism is not new. Even leftists with a Jewish heritage hate Judaism.
Indeed. Although many of the connections and aspects are not well known, even by scholars. For instance the essay linked below incidentally relates how the better known "Holocaust Revisionism" movement in America and England was actually an important from France where it was initially fostered by small leftist-extremist groups:
Partners in Hate
Chomsky and the Holocaust Deniers
by Werner Cohn
http://wernercohn.com/Chomsky.html