Picking up from yesterday he's my friend J's response,
American Jews are Democrats for a number of reasons, but first and foremost because our religion teaches us that while the pursuit of financial success is valuable, there is no higher value than serving God through the creation of our own just societies. To modern, especially reform Jews that means social justice through improving other's lot in life and caring for those who cannot care for themselves. This reasonably leads modern Jews towards the Democrats.
I'd suggest that aside from health care (of which Jews overwhelmingly support health care reform) Jews tend to be relatively conservative Democrats, though some lean further left. I think there is some additional leeriness towards the Republicans, especially the Christian right due to the underlying nature of their appreciation towards Israel.
To some extent it reminds me of Aesop's fable of the scorpion and the tortoise. If you don't recall, the scorpion is at one bank of the river and cannot figure out how to cross whent he turtle comes by and suggests the scorpion swim across. The scorpion replies that he cannot swim, and suggests the tortoise carry him across. The tortoise is leery and suggests that he would get stung by the scorpion. The scorpion eventually convinces the tortoise that it is in the scorpion's best interest not to sting the tortoise, otherwise the scorpion will die. The tortoise is convinced and begins to carry the scorpion across the water at which point the scorpion stings the tortoise. As both are falling into the water to their deaths the tortoise asks why and the scorpion responds, "It is my nature to sting." The moral being, no matter how friendly the enemy can seem, you may not be able to trust them if your natures don't lead you to the same end. (clearly paraphrased).
I think that Jews rightly suspect the evangelical right as scorpions in their midst as Jews continue to work to find their place in the American political landscape. While Israel will always be an overriding issue for Jews, no politician in his right mind will shun Israel. It's too much in their own interests and in the interests of US national security.
As an aside, prioritizing business and personal wealth as a reason that Jews should be politically motivated towards another party is almost a vague anti-semitic throwback to the notion of Jews running the banks and such. While not a direct link, prioritizing finances in the context of how Jews have been treated by other culture carries somewhat of an anti-semitic undertone.