A large percentage of Jews -- including affluent Jews -- blindly vote Democrats into office because voting for Democrats is Jewish tradition. Traditional voting for Democrats often times is not in the Jewish community's interest. Traditional Jewish voting was so strong, that they were blind to the 23 members of congress who voted in August, 2006, against the House and Senate resolutions of support for Israel. Nineteen of the 23 were Democrats (details).
When I ask many Jewish liberal voters who voted for former president Jimmy Carter, who In January 2007, wrote an anti-Israel book "Palestine; Peace not Apartheid" and who met in Damascus with Khaled Meshal, the head of the Palestinian militant group Hamas, in a direct rebuke of the Bush administration's campaign to isolate it, the typical answer is "I didn't know that about Jimmy Carter when I voted for him." They should have known what liberal Harvard proffessor, Alan M. Dershowitz wrote when he came to his senses: Ex-President For Sale