The decades surrounding the opening of the twentieth century saw one of the most significant shifts in the character of American public life. A political order dominated by decentralized parties and a limited state gave way to one defined by interest group activism, weaker parties, and more vigorous government. Scholars argue over the degree and extent of these changes, but few quarrel with the claim that public life looked substantially different by the end of the Progressive Era. Americans accepted interest group pluralism in principle and in practice by the 1920s, and the ideal of a politics devoted to an undifferentiated common good lost much of its persuasive power.²

     That these new arrangements took root in the wake the Progressive Era is one of the central ironies of American political history. Progressivism, however defined, was distinguished by a powerful impulse to advance the public interest over special interests. Reformers and politicians of the day loudly pledged their devotion to "the people"—a monolithic entity—in its battles against trusts and corrupt bosses and promised to pursue the common good. "This is a movement springing from the needs and the hearts of the people of the United States," Theodore Roosevelt proclaimed as he campaigned for the Presidency on the Progressive Party ticket in 1912. "The business of government is to organize the common interest against the special interests," his principal opponent, Woodrow Wilson, declared. Roosevelt and Wilson both used such rhetoric, as did a multitude of office seekers and activists during the Progressive Era. Yet their efforts yielded a politics in which the idea of the common good seemed more elusive than ever.³