I think Jackie Mason has it right when he says that all Jews feel guilty because of their success and are essentially self-loathing to the core as a result.

There’s also the moral erosion implicit in secularism, to which most Jews seem wedded.
Then there is the intellectual elitist strain, which forbids contamination by the American salt-of-the-earth types like Sarah Palin, and you have some important contemporary pressures. They are Rush-proofed and commonsense-proofed.