Scholarship on the political development of the United States since the 1960s is dominated, not surprisingly, by social scientists. Such recent events fall within the penumbra of “contemporary history,” the standard research domain of social scientists but treacherous terrain for historians. Social scientists studying American government and society generally enjoy prompt access to evidence of the policy-making process–documents from the elected and judicial branches of government, interviews with policy elites, voting returns, survey research. Historians of the recent past, on the other hand, generally lack two crucial ingredients–temporal perspective and archival evidence–that distinguish historical analysis from social science research. For these reasons, social scientists (and journalists) customarily define the initial terms of policy debate and shape the conventional wisdom. Historians weigh in later, when memories fade, archives open, and the clock adds a relentless and inherently revisionist accumulation of hindsight.