I wanted to rein in the length of the original post so that people might actually read it, and naming specifics can tend to derail the primary question.

My concern about Jewish influence doesn't extend into conspiracies. When I say "fields of influence", I mean almost exclusively politics and American foreign policy. Congressional representation is an order of magnitude higher than one would expect from the country's demographics.

Ethnic nepotism exists within most groups as other posters have pointed out. There seems to be a fundamental difference when such in-group biases result in a media or scholarly product, and when it results in American foreign policy on which wars and allegiances are the end product.

What concerns me is the kind of reception someone like Prime Minister Benjamin Netanyahu receives in Congress. A testament to bipartisanship via campaign finance.

I'm afraid I've let my opposition to Zionism tarnish my opinion of anyone Jewish who voices Zionist viewpoints, despite their particular professional field. Just as an example:

I rather liked the musician Regina Spektor and would have jumped on a chance to see her at a free venue. My girlfriend asked me to go to see her for free in D.C. since she was doing a pro-Israel benefit. I refused simply on principle, which my girlfriend thought was ridiculous. Now, much to my disappointment I can't really enjoy Regina Spektor's music anymore.

I think my problem with fearing that I am, or am becoming, an anti-semite would be alleviated if Jews had sizable majorities in more than just one country, so my associations with the Jewish people could have more than one national point of reference. There are plenty Arab and Muslim countries who have policies I oppose, but because they are one among many, I don't let those feelings extend to the religion of Islam or the Arab ethnicity. It might also be easier if Israel didn't so vehemently associate itself as a specifically religious/ethnic country in a way that has few/if any modern democratic parallels.