Rightly or wrongly Princeton has always been perceived as a welcoming campus for the rich, famous and "white". That does not include "Jews" who have had a long history of encountering anti-semitic sentiments on the famous campuses.
Columbia to its credit was the first IVY college to open its arms widely to accept talented students who were Jewish. Franklin D Roosevelt, yes that famous man, who once sat on Harvard Corporation that governed the university, was alarmed by the increasing number of Jewish students at Harvard. He said: "We cannot allow so many Jews to come to Harvard".
Since then Harvard and others have put that kind of mentality behind them. Princeton, the northern-most southern college in America, appears to be slow in adjusting. Or perhaps it has chosen to be where it is.
Read this article from the Daily Princetonian