[AmishDude]

Penniless Jewish immigrants who came to this country during the late 1800's and early 1900's found the Democratic party best represented their interests.

Represent is a bad choice of words. Exploit would be much more appropriate. Such was the experience of most groups that emigrated to the Northeast. Remember, we're talking about Tamany Hall here.

The anti-Semitsm of the Left is a new phenomenon in America

I wouldn't say that the Left had been immune to anti-Semitism, but it is true that it wasn't a driving force in the American Left until very recently. Interestingly, eastern European communists were quite anti-Semetic.

[liberallarry]

Represent is a bad choice of words

Represent and exploit are both correct. The problem occurs whenever you expect others to defend your interests for you.

Interestingly, eastern European communists were quite anti-Semitic

True. But I don't know the details or causes - probably the eastern Europeans were anti-Semitic no matter what their politics.

[Valin]

Anti-Semitsm, like all forms of racism(I'm not sure that's really the word I'm looking for) is an equal opportunity attitude it can be found right across the political/economic/social spectrum.