Abstract: Contributing to the growing legal literature on social movements and constitutional culture, this Article uses the widespread public mobilization that occurred around Gutter v. Bollinger and Grata v. Bollinger as a point of departure for its analysis. These cases are apt for such a discussion because they generated scores of amicus briefs and numerous public opinion polls and, most important for this analysis, featured a group of intervenors styling itself a "mass movement" for social justice. Taking an interdisciplinary approach, this Article considers the Gutter intervenors' experience in light of social movement history and the social science and legal literature on mass movements. Challenging the legal literature, this Article concludes that social movements and juridical law are fundamentally in tension. The legal literature assumes not only that the two are compatible, but also that rights talk is especially inspirational to, and efficacious for, social movements. This view overlooks an important distinction between the definitional and inspirational roles that law in the courts can play in protest movements. Social movements may profitably use rights talk to inspire political mobilization, although less successfully than legal mobilization theorists assume. But social movements that define themselves through law risk undermining their insurgent role in the political process, and thus losing their agenda-setting ability. Viewed within this framework, the Gutter "mass movement" failed to significantly impact the constitutional order. Instead, the intoners engaged in a single-issue political and legal reform campaign, which achieved only moderate success. Their limited success demonstrates the tension between social movement tactics and litigation as tools of social change.