There is no more dangerous third rail in American politics and journalism than antisemitism in the black community. It is an issue that has mostly simmered in obscurity for decades for the very simple reason that it can be ugly to talk about. But we have to talk about it. With rapper Kanye West's recent anti-Jewish rantings, with basketball star Kyrie Irving sharing antisemitic movie trailers, and, most importantly, with Haredi Jews now routinely assaulted in places like Brooklyn, New York, silence is no longer an option. The question is how to best combat the antisemitism that has lurked, not...