Rep. Alexandria Ocasio-Cortez (D-NY) refused Sunday to visit the Auschwitz concentration camp, after a Jewish group had invited her to tour that camp and others this summer to educate herself about the facts of the Holocaust. Last Monday evening, Ocasio-Cortez compared detention facilities for illegal aliens caught crossing the U.S.-Mexico border to “concentration camps,” adding the phrase “never again,” which commonly refers to the Nazi Holocaust. The remark drew outrage and criticism, even from fellow Democrats. Nevertheless, Ocasio-Cortez doubled down, first claiming that she had not been referring to Nazi Germany, then drawing parallels to the U.S. internment of Japanese-Americans...