Threats to American unity are not unique to modern times. In the 1960s, the assassination of President Kennedy, the tension of racial strife, the political extremes of the Radical Right with its John Birchers and the Radical Left with its threat of Communism all raised critically urgent questions relative to our national unity, to our political stability, and to our vaunted respect for the rule of law. The Challenges to Democracy is an assessment of the foundations of political unity in the United States. The American consensus, as Murray Clark Havens defines it, emphasizes a set of values and procedures that most Americans, since the adoption of the Constitution, have accepted in principle: religious tolerance, individual freedom in intellectual and cultural matters, the importance of education and intellectual effort, settlement of internal conflict through peaceful and political processes, the supremacy of law, a high and generally rising standard of living, and, since the Civil War, racial compatibility. Never in our history have the ideals of this consensus been fully achieved, but as long as the majority of our citizens accept the validity of those ideals and the democratic procedures for realizing them, the basic American political unity is not threatened. However, when citizens who cannot accept the elements of the American consensus become influential enough to block the democratic process, then that consensus is threatened. Havens shows how such threats have come to us all through our history—the Civil War, racial and religious bigotry, the Ku Klux Klan, Huey Long, Father Coughlin and other extremists of the desperate thirties, McCarthyism. He discusses contemporary dangers to American unity such as those connected with the acceptance of the African American, religious friction in politics and government, the Radical Right and the Radical Left, and our foreign policy as an expression of the American consensus. The broad conclusions of this study are that our national unity is continuously in jeopardy, with frequent recurrences of serious questions as to the permanence of some of the patterns we have always associated with American government, but that our democracy is possessed of considerable potential for survival because of our deep national commitment to democracy and because of our even deeper nationalism.