It’s a deep question. Italian-Americans are another group to look at. They also “became white” after a lot of struggle. They also have a history of not being the most inclusive people after winning their own acceptance.

Is the Jewish experience difference because their trauma was deeper and more violent? Or is it all just an accident? Did the Hadassah movement and traditional Jewish association with liberalism set them on a path that made exclusion less likely just out of social inertia?

I really have no idea.

But I suspect the deep trauma idea may be worth looking at.