In recent years, widespread efforts to "opt out" of state tests have pressured school districts, states, and the federal government to reconsider the extent and limits of state assessments. This activism raises a number of questions about the relationship between democratic participation and public institutions. What is the relationship between state authority, expertise, and public opinion? In what ways should citizens be engaged in the public policy process? Are there times in which the state—in subverting the will of citizens—might be reshaped through public activism? We draw on Dewey's concept of "the public" to explore the democratic qualities and consequences of this activism. We highlight two conceptual resources from Dewey's 1927 The Public and its Problems: how publics are formed when they share consequences, and the role of public expertise in addressing social problems. Through these resources, we argue that the opt out movement might be understood as an overlapping set of publics promoting democratic engagement in education. At the same time, Dewey's understanding of the public poses critical questions about the democratic qualities and broader consequences of this emerging movement.