On Tuesday, tens of thousands (almost 300,000, according to organizers) of American Jews gathered in Washington, D.C. for a March for Israel, the stated aims of which were to show support for Israel, call for a release of the more than 200 people held hostage by Hamas, and to fight antisemitism. These are not particularly specific calls, and the fact that they were vague—vague enough for lots of people to see themselves in—was intentional. The march was meant to allow lots of different types of American Jews to come together, each with their own interpretations of what it means to...