The good news from the recent donnybrook over Tucker Carlson’s interview with Nick Fuentes, the Hitler fanboy with a sizable social-media following, is that it has at last forced conservatives to reckon with the sewer pipe of antisemitism bursting through their walls. Better news: Many have risen to the occasion. That includes Sen. Ted Cruz, who called out his fellow Republicans for being too timid to condemn Carlson; The Wall Street Journal’s editorial board, which denounced “this poison in their own ranks”; and Heritage Foundation people who resigned in disgust after Kevin Roberts, the organization’s president, offered a lickspittle apologia...