Could it be because most US Jews are not truly Jewish??? Just like most US Christians often don't act like Christians. Why are many NE Christians knee-jerk liberals or 'milque-toast' moderates?
The Irish became "part of the establishment" through lib politics, the Italians and Portuguese brought with them corrupt politics of their homelands, the Poles became hardcore trade unionists. Let's alsonot forget about the good Scandanavian Evangelicals in Minnesota. :-)
Of course, with more wealth and assimilation, many of the descendents of those settlers became selfish yuppies and soccer moms.