To me, the real mystery is why Jewish Americans are, for the most part, Democrats.
And Catholics too
It's very simple: Jews and Asians mostly live in cities. Cities vote Democrat, rural areas vote Republican, suburbs are a mixed bag. Cities are communes where most everything is shared and little property is personally owned. As farm automation continues, young Americans needing jobs are forced into the communes where most of them eventually become communists.
While many ordinary Dems were anti-Semitic, they weren't the ones keeping Jews out of elite universities, jobs, or clubs. Rich, white, wealthy Republicans were. And that's why many Jews identify with the Thief Party...oh, excuse me... Dem party to this day.