Crossing movement boundaries: Factors that facilitate coalition protest by American college students, 1930-1990

Staging events with a large number of participants is a central means by which collective action movements exercise power. Creating broad coalitions that cut across movement boundaries is one way to mobilize these large numbers. In spite of this fact, most studies of social movement coalitions focus on individual movements, analyzing them in isolation. This article explores the conditions under which organizations form alliances across movement boundaries, and examines whether these cross-movement coalition events are facilitated by the same factors that inspire coalition activity among organizations active within a single movement. I use event history methods to analyze data on 2,644 left-wing protest events that occurred on college campuses between 1930 and 1990. I find several differences between the factors that facilitate cross-movement and within-movement coalition events. The availability of resources is important to within-movement coalition events but not to cross-movement coalition formation. Local threats inspire within-movement coalition events, while larger threats that affect multiple constituencies or broadly defined identities inspire cross-movement coalition formation. The activity of multi-issue movement organizations is associated with higher levels of all forms of protest, including single and cross-movement coalition events. This research contributes to social movement theory by demonstrating that political threats sometimes inspire protest, and that organizational goals influence strategic action.