Original sentence: The related concept of Jewish self-hatred has been described as "an entirely bogus concept",, and one that allegedly "serves no other purpose than to marginalise and demonise political opponents" and that, critics say, is used increasingly as a personal attack in discussions about the "new antisemitism"
Edited sentence: The related concept of Jewish self-hatred has been described as "an entirely bogus concept", which "serves no other purpose than to marginalise and demonise political opponents" and is used increasingly as a personal attack in discussions about the "new antisemitism"