I must admit that this is a question which has perplexed me from time to time. The question has been answered in a book called Why Are Jews Liberals? By Norman Podhoretz.
According to Mr. Podhoretz:
American Jews grew up in liberal homes heavily influenced by the ideology they inherited from their Eastern European ancestors. There, in Russia and Germany, you either followed the Kaiser´s or the Czar´s line or were a Communist.
In the New World, communism morphed into socialism in the early years of the twentieth century (and morphed into liberalism during the reign of FDR).
In the U.S. Jews stayed in the liberal camp not just out of conviction but also from fear of the Christian right. When fundamentalism reared its head in American politics, they feared that anti-Semitism would not be far behind. And, as the anti-communism of the McCarthy era targeted the Jewish intellectual establishment, their dependence on Democrats only increased.
It came as a shock to America´s Jews that first Nixon, then Reagan, and finally Bush-43 emerged as Israel´s strongest supporters. And it came as a total shock when the religious right became Israel´s strongest backer based on its biblical conviction that God had promised the Holy Land to the Jewish people.
But, by then, religion and even Israel had weakened their holds on American Jewish hearts.
But Podhoretz´ book, written before Obama manifested such an anti-Israel bent, leaves unanswered the question of whether the pro-Palestinian bias of the current administration, not to mention its war on prosperity, will drive Jews away from their liberal moorings. The answer probably lies more with events than within Jewish thinking. As it becomes more anti-Israel and anti-wealth, the Party will leave the Jews before the Jews realize it has left and themselves leave the party.
Well, that certainly explains some of the mystery. However, it does not explain the public outrage against Israel by the many Jewish organizations who believe that Israel does not have a right to defend itself.
I have to believe there is a bit of a Marianismo type of effect going on here, in that it seems to be the belief of many of the Jewish population that they are supposed to suffer the abuses of others as part of their faith.
What else would explain their myopic support of a political class of Socialists who heavily favor the radical agendas of the very hate filled people who seek the death of the entire Jewish Population?
As with many things in life, there never seems to be a rhyme or reason. I tend to think that Liberals have either done to many recreational illegal, drugs, or are suffering from the effects of too much fluoride in their drinking water and the brain washing that they substitute for education.
Either way, there is certainly something there that verges on the edge of insanity without quite going completely over to the dark side. Though many of them eventually do without realizing it.