I don't see anything wrong with the Jewish people looking out for their interests, but as a scientifically-minded person I'm more interested in objective analyses of the situation (as in the mentioned book) than vague anecdotes like 'lots of people think that Israel is right'.
If American Jews are an order of magnitude more politically active than other groups, we shouldn't be ashamed to admit it. It's an interesting sociological phenomenon that needs to be studied.