Tocqueville, considering how Americans compare their nation with others, observed that general ideas about politics testify to the weakness of human intelligence. “The Deity does not regard the human race collectively.… Such is, however, not the case with man. … Having superficially considered a certain number of objects, and remarked their resemblance, he assigns to them a common name, sets them apart, and proceeds onwards.”

As it is for human beings, so, too, for political scientists. And of the generalizations which have helped Americans and American political scientists organize the confusing mass of differences and similarities between this country and others, none has been more important and enduring than the notion of the uniqueness of the American political community. This conception is reflected in the split within the discipline between those who study the U.S. political system and those who study comparative politics, a field understood to encompass various foreign countries. The rubric that in the American Political Science Review until the 1950s used to read “Foreign Governments and Politics” has been replaced by a subsection of the book reviews that is entitled “Comparative Politics.” But today as in the past, it is rare to find teaching or research in political science that truly integrates the analysis of American politics within a comparative framework.

Why this should remain the case is difficult to understand, for over the past half-century there have been many shifts in the discipline and in the world that challenged the premises of research based on American exceptionalism. Already in the interwar period, significant work in political science was moving beyond configurative case studies of individual countries. C. J. Friedrich's important Constitutional Government and Democracy (1937), indeed, included the United States in its examination of how well certain general political theories explained the experiences of major political systems. Whatever reservations one might have had about the methodologies of comparative research on which Friedrich relied, the broad influence of his work promised a new integration of American politics into an expanded field of comparative politics.