My children are blessed to have been raised in a country different from the Germany of the 1930s and the Poland of the immediate postwar era. Both of my parents are refugees from European antisemitism, and my mother’s comments about her experiences in Poland can seem mysterious to my kids. They haven’t been raised with material exhibitions of antisemitism, and our discussions about it over the years have seemed more like lessons in history. But antisemitism is on the rise again in the United States. Harmful tropes have returned to explicit politics, with help from the last president. Meanwhile, remarks...