Daniel Greenfield writes in his blog Sultan Knish, The Jewish and Post-Jewish Vote, 10/25/12
American Jews can be broken down roughly into the products of three periods of immigration.
This second wave turned rigidly Democratic under the rough tutelage of the urban political machine and the gentler tutelage of an educational system meant to turn Jewish, Irish and Italian immigrants into proper Americans– and to the people running the melting pot machine, Americanism meant Liberalism. They didn’t always succeed, but they succeeded well enough to build an immigrant electorate for the Democratic Party.
The Liberal Jew was a product of that melting pot which stripped him of his cultural identity and his religion, leaving behind a hole that he filled with the messianism of liberal politics. The graduates of the melting pot were economically successful and well educated, but they had lost their sense of self. Looking for that sense of self, they became devout attendees of progressive politics, filling the hole with bitter greenie humor that poked fun at everything, especially themselves.
American Jewish identity became liberal identity, and the massive cultural hole was filled with humor which has found its natural end in the degraded vaudeville of Woody Allen and Larry David or the bitter frustrations of a Philip Roth. The trinity of FDR, JFK and Obama became their faith and their identity became a series of in-jokes about eating Chinese food on Christmas. Like the Spanish Jewish Conversos, they had a secret identity but they no longer knew what the secret was.
This second wave of immigration would define American Jewish identity. It is the invariable focus of American Jewish literature and the PBS specials on the American Jewish journey that run before major Jewish holidays. It is also on the way out for the simple reason that such an identity is in no shape to be passed on to the next generation. The copying errors of cultural DNA in such bad shape mean that each generation ends up knowing less about who it is than the last one. And that means each generation is also less likely to be Jewish and more likely to be liberal.
The second wave’s DNA copying errors has produced a lot of abortion and gay rights activists, it hasn’t produced a lot of children. Like all cultural mistakes, Liberal Judaism is wiping itself out. It leaves behind a lot of jokes, some inventive pop products that defined 20th Century Americana and some Unitarians with Jewish roots who fast for Gaza and denounce Israel.
Many of my non Jewish friends are puzzled about the strong liberal tendency of Jews to support liberal candidates. Greenfield offers this perspective, though it is written from a strong conservative view. The third wave which are the more current refugees from communist oppressive states tend to be more conservative and far more fertile. For demographic reasons alone we may be witnessing a major transition in the Jewish voting patterns.