This long response to the "Israeli lobby" article previously discussed makes some interesting points about how the lobby can be used as a convenient excuse to facilitate, rather than shape, policies that have their roots in racism:
American perceptions of and policy toward the Middle East are characterized by an easy and reflexive anti-Arab racism with roots in our history and repudiation of slavery (a denigration of dark skin coupled, ironically, with an American cultural imaginary in which Arabs—whether in Sudan or in the Gulf–are still inveterate slavers, both evil and historically backward); in our frontier ideology of settlement and rugged self-reliance (so consonant with the Zionist myth); and in the longstanding literary and media depictions of Orientalism, which help us to write off the concerns of Arabs and Muslims. Unlike Jews since the middle of the twentieth century, and Italians, Poles, and Irish before them, Arabs and Muslims have not been accorded the status of “white people” in the United States, and are left vulnerable to sometimes open and socially approved discrimination, insult, vandalism, harassment, and threat of violence. Internationally, these predispositions help us attribute Middle Eastern poverty or political repression to personality flaws endemic to the region (corruption, zealotry, tribalism, sexism) rather than to structural or historical factors.I think it's a two-way street: the "lobby," in its manifest forms, encourages and promotes such thinking, and there are reasons to be weary of it that have to do with the corruption of American politics (also carried out by other lobbies.) But, if you've taken the time to read the whole lobby article, you might want to read this long piece about it -- it has a lot of interesting thoughts.