Utilizing survey data for demonstrators at a national antinuclear rally (N=420), as well as a thematic review of the antinuclear literature, this paper examines ideological consensus and diversity evident in the national protest over nuclear power. Our findings reveal a significant amount of overlap between the ideological themes of the movement and the individual beliefs of antinuclear demonstrators. While the demonstrators display a diversity of opinion in their reasons for opposing nuclear power, there is a consensus of belief that future solutions entail shutting down nuclear plants and replacing them with alternative energy sources and conservation programs. Moreover, there is a consensus of belief among demonstrators regarding the values underlying their rationale for movement participation, values that both challenge and incorporate larger dominant beliefs of American society. The implications of these findings for movement theories are suggested.