Just when it seemed Michael Richards was about to leave the most troubling incident of his career behind, his publicist is having to explain how the comic could consider himself to be Jewish.Last week, crisis management expert Howard Rubenstein acknowledged that Richards had shouted anti-Semitic remarks in an April standup comedy routine - well before his appearance earlier this month in which he harangued hecklers with the n-word. But he defended Richards' language about Jews, saying that the comic "is Jewish. He's not anti-Semitic at all. He was roleplaying."As Rubenstein's assertion circulated, Jewish organizations and commentators pointed out that the man who played Cosmo Kramer on Seinfeld has not converted to Judaism and neither of his parents are Jewish.Which makes him ..."Technically, not having been born by blood as Jewish and not formally going into a conversion, it was purely his interpretation of having adopted Judaism as his religion," Rubenstein said on Tuesday. "He told me, 'I'm Jewish,' when I asked him."He said there were two mentors who raised him and who had a big influence on his life, and they were Jewish. He said, 'I agree with the concepts and the religious beliefs of Judaism and I've adopted Judaism as my religion,'" Rubenstein said. "He really thinks of himself as Jewish."What do some Jews think?"You can't 'feel' Jewish. It's not a matter of feeling. You can convert to Judaism. You can't not convert to Judaism and then be Jewish," said Rabbi Marvin Hier, founder and dean of the Simon Wiesenthal Center in Los Angeles.Hier defined being Jewish from two perspectives, if someone hasn't gone through the process of formal conversion."From the Orthodox point of view, if that person has a Jewish mother, he would be considered Jewish," Hier said. "In the Reform tradition, there's also a patrilineage. Under those categories, he would not fit."Rabbi Mark S. Diamond of the 280-member Board of Rabbis of Southern California agreed."There are many people who appreciate Jewish customs, who may embrace aspects of Jewish culture and practice, but that does not make them Jewish," he said.After his tirade came to light, Richards apologized on David Letterman's Late Show on CBS, saying his remarks were sparked by anger at being heckled, not bigotry.He also apologized to the Reverend Al Sharpton, and apologized Sunday on the Reverend Jesse Jackson's syndicated radio program. Rubenstein said Richards wasn't available for an interview Tuesday. "He wants to rest," the publicist said. "He's been talking to his psychiatrist."