The metaphor that America is like a garden is not a gimmick, but powerful refutation of neoclassical economics. If you think that human beings are atomized individuals who only make rational decisions in a marketplace with the goal of maximizing their utility, Liu and Hanauer will not only disagree, they will argue that science has proven that view to be wrong.

Most Americans have divested themselves of ownership of their own political system. ...most Americans have lost faith in themselves as members (gardeners) of a political community (garden). I dare say that most denigrate the role of politics in their lives.