In a letter to W. T. Barry, James Madison wrote that "a popular government, without popular information or the means of acquiring it, is but a prologue to a farce or a tragedy, or perhaps both." Much like Madison's words to Barry, the title of this book Communicating Politics: Engaging the Public in Democratic Life-is based on two principal assumptions: that an informed public is crucial to democracy; and that the key to assuring such a public is the availability of engaging yet informative and accessible campaign communication. While many of the studies and essays contained in this volume are devoted to assessing, and making recommendations for improving, the current state of campaign communication, this chapter provides an overview of what Americans know about politics and why it matters. The information presented here draws heavily from my previous work in this area (Delli Carpini & Keeter, 1996). The literature on political knowledge provides fairly compelling evidence for five characterizations regarding what Americans know: (1) the average American is poorly informed but not uninformed; (2) aggregate levels of political knowledge have remained relatively stable over the past 50 years; (3) Americans appear to be slightly less informed about politics than are citizens of other comparable nations; (4) "average" levels of knowledge mask important differences across groups; and (5) knowledge is tied to many attributes of "good" citizenship.