It is a function of social and political theories that they can be applied to a wide variety of phenomena and texts. One could, for instance, use either functionalist or conflict theory to illuminate the reading of Bobos in Paradise. Both theories will persuade some readers, but they will probably be readers who preferred that particular theory in the first place.
David Brooks describes the bobos (a word of French origin, meaning "bourgeois-bohemian") as the new upper class. He points out that it used to be tell who was bourgeois and who was bohemian. Now, the banker, the professor, the executive and the artist all dress in the same way, drink the same coffee in the same coffee shops, and share the same liberal, global values. The bobos dislike conspicuous consumption and obvious brands, but spend large sums of money on such luxuries as foreign travel or kitchens and bathrooms made from natural materials.
An adherent of any functionalist theory of inequality would say that the bobos are an inclusive meritocracy. Their values come from their education, and the fact that they are less brash and consumerist that the stereotypical 1980s yuppie show that their class has become more thoughtful and developed more humane values, justifying its position at the top. Conflict theorists would retort that structural inequality persists in exactly the same way that it always has. The bobos have learned to camouflage themselves, but they are really exploitative capitalists clinging onto wealth and privilege while pretending to have a social conscience. Both theories will attract adherents based on pre-existing ideology.