If this model of advocacy sounds familiar, it should. The same basic structure explains the success of the National Rifle Association and the pro-Israel lobby exemplified by AIPAC. None of these organizations is breaking the rules. To the contrary, their success reflects the basic structure of U.S. politics. Those who support gun rights care deeply about the issue: They're the essence of a concentrated lobby. Those who would regulate guns are almost by definition more diffuse. They might be motivated after an event like the Newtown, Connecticut, shooting, but over time, diffuse interests return to their natural state of diffusion. The pro-Israel lobby succeeds not primarily because of its financial capacity or disproportionate cultural influence, but because there is no concentrated pro- Palestinian lobby of any real size in the U.S. Polls suggest that many Americans favor the idea of evenhandedness between Israelis and Palestinians (whatever that might mean to them). But any such impulse is highly diffuse, whereas the small number of Jewish Americans who pay the most attention to promoting Israel's interests as they see them are highly focused and concentrated.