Richards claimed to be Jewish to try to get a pass for his antisemitic outburst, but he is not Jewish. He was raised Catholic, has no Jewish ancestors, and never converted. Like Whoopi Goldberg, he "feels" Jewish, because he is a thief and an appropriator. A lot of people think of him as Jewish because he plays into the media stereotype of the neurotic, weird New York Jew, on a show that was all about that.
Actual Jewish people can be antisemitic. Bobby Fischer is a good example, as are Gilad Atzmon, Ron Unz, and Karl Marx. Similarly, black people can be racist (Diamond & Silk) or gays can be homophobic (Roy Cohn). Some of it is from having been raised with no connection to the community and feeling the very concept of Jewish community needing protection from violence and falsehoods to be unnecessary; some of it is weird role-playing self-abnegation; some is mental illness and attention-seeking.
Actual Jewish people can be antisemitic. Bobby Fischer is a good example, as are Gilad Atzmon, Ron Unz, and Karl Marx. Similarly, black people can be racist (Diamond & Silk) or gays can be homophobic (Roy Cohn). Some of it is from having been raised with no connection to the community and feeling the very concept of Jewish community needing protection from violence and falsehoods to be unnecessary; some of it is weird role-playing self-abnegation; some is mental illness and attention-seeking.