Only by aligning with parties can movements create the possibility of not merely influencing policy but of transforming a polity. Only through parties, Schlozman argues, can social movements in the United States hope to rule. Movements, which are evanescent, rarely lasting for even a generation, must “confront parties” if they are to exercise any lasting influence over law and policy (18). In this confrontation, movements offer ideas, connections to social groups and voters, volunteers, and money. Parties, in return, offer power, or the chance to shape the “contours of politics” (242, 246).
In the nineteenth century, parties had independent access to the resources necessary to obtain and maintain political office: They had their own money, their own organization, and their own benefits (like patronage jobs) with which to reward their supporters. But the reform of the Progressive Era left parties less autonomous and more dependent on outside groups for...