Selectorate theory posits that all regimes can be thought of as beholden to subsets of the population, called selectorates. Democracies have subsets that are essentially the entire population, or the electorate. Dictatorships are said to have a much more limited set of the population that is in the selectorate.
Egypt shows a fundamental flaw in this theory. The masses matter. They have always mattered and always will. It is true that at some level the masses matter “less” in a dictatorships than in a democracy. The idea that the interests of the full population can be totally and safely ignored will hopefully leave the intellectual realm more gracefully than Mubarak seems to be leaving Egypt. However, I imagine that like much of the Zombie theories that continue to dominate economics, selectorate theory will keep on showing up and devouring brains.