Responsible political leaders — from President Joe Biden to Gov. Kathy Hochul to Mayor Eric Adams — have rightly deplored the sudden spike in antisemitism, especially on college campuses. Yet the crisis calls for more than sympathetic words and token gestures. America needs a serious crackdown on this festering cancer. On Tuesday, FBI director Christopher Wray testified before lawmakers that antisemitic threats are “reaching historic levels.” He noted Jews represent just 2.4% of the population yet “account for something like 60% of all religious-faith hate crimes.” Anti-Jewish protests have broken out in major cities, and Jewish students at have endured...