Democracy, unlike any other form of government, demands that citizens take responsibility for their politics. And yet, over the past fifty years, observers of American democracy have worried that Americans are failing to do so. With occasional exceptions, voter turnout and civic engagement are declining, and the average citizen's knowledge of public affairs is flimsy at best. Citizens' political posture is mostly passive: they receive political propaganda designed by marketing professionals and consume staged political spectacles that are scarcely distinguishable from other forms of "reality"...