Though many explanations have been advanced, my pet theory is that Jewish "liberalism" persists because it is based in long standing tradition. Just as American and English political tradition is derived from Anglo Saxon roots which valued the individual, freedom and personal liberty, Central and Eastern European political tradition has its roots in the birth of socialism. And the great influx of Jews into the United States in the early 20th century came from central and eastern Europe, so they would have been carrying this leftist political tradition with them. Their political tradition has deep roots, it continues to be handed down, generation to generation.
I have at least a little hope that things may change, I personally belong to both Jews for the Preservation of Firearms Ownership and the Jewish Republican Coalition. I have a close buddy (Jewish) who has seen "the light" and become a conservative. Though intellectually conservative, emotionally he still retains "liberal" instincts...tradition.
But I promise you that the greatest threat to world Jewry does not come from fascism on the right (i.e. Le Pen in France)but rather from socialists on the left. The French government refused to label the recent burning of Synagogues in France as terrorism or hate crimes because the perpatraitors were arab citizens who aligned themselves with socialist factions of the government-- and the government qualified its condemnation of these acts by stating the hostility was understandable in light of Israel's "occupation" of Palistinian territory!
What does attacking French Jews have to do with Israel? On September 12th, had French Jews gone out and burned down Mosques in retaliation for Arab-backed terror against the U.S. and U.S. Jews how quickly would the French government condemned this hypothetical retaliation? The fact is there was no backlash against Muslims after Sept. 11th because civilized people don't scapegoat a whole race or culture based on the deeds of a minority of them. But the French and the arab terrorists they sympathize with are not civilized; and liberals are not capable of making this distinction.