The recent hostage crisis at Congregation Beth Israel in suburban Fort Worth, Texas, is a reminder that antisemitism is a growing and global scourge, one that has forced synagogues across the U.S. and Europe to post armed guards and bar their doors. The idea that members of Congress would block any efforts to combat it is shameful. Yet that’s arguably what Senate Republicans are doing. Among the hundreds of administration nominees awaiting a confirmation vote is Deborah Lipstadt, a renowned Holocaust scholar and President Joe Biden’s pick to helm the State Department’s office for combating antisemitism. Republicans on the foreign-relations...