Since the Jacksonian Era, American intellectuals have generally hailed the broadening of political participation as a sign of ineluctable progress and unparalleled historical importance. Some commentators voiced reservations about the pace and extent of democratization, but their voices were countered by those, like Theodore Parker, an important influence on Abraham Lincoln, who interpreted American history since the Revolution as demonstrating the superiority of “a government of all, for all, and by all.” In contrast, many more European observers, like Gustave Le Bon, were more skeptical of the mass age, fearing the emergence of demagogues through the gullibility of “the mob.” Terrorized by the Nazi and communist dictatorships, Hannah Arendt, a German émigré on American soil, formulated her disappointment in the promise of expanding democracy thus: “Totalitarian movements are mass organizations of atomized, isolated individuals.” These contrasting judgments not only exemplify distinctive historical experiences between the Old and New Worlds, they also circumscribe the range of consequences of a transformation that intensified around the beginning of the twentieth century.

Instead of simply constituting a success story, the experience of mass politics suggests two contradictory readings. On balance, the record of mobilization in the United States supports an optimistic assessment because during the course of the twentieth century, the political system came closer to reflecting the diversity of the nation's population and interests than at any previous time. Despite pitched contests over who could participate in public life, the mass mobilization of constituencies was an essential facet of American public life throughout the twentieth century. In many ways, this development appears to have been both emancipatory and democratic in effect, as exemplified by the campaign for women's suffrage before World War I, the industrial labor movement during the 1930s, the civil rights movement of the 1960s, and the environmental movement more recently. Some elements of the German story also support such a positive representation. During the semi-constitutional empire, the universal male suffrage of Reichstag elections extended participation and prepared the ground for the liberal constitution of the Weimar Republic. After the dark interlude of the Nazi dictatorship and the continuation of repression under the communists in the East, the re-democratization of the Federal Republic ultimately succeeded in turning the longing for participation back into a parliamentary direction.