This article analyzes civil society participation in the free trade debate by focusing on networks that opposed the Central American Free Trade Agreement (CAFTA) in El Salvador. Drawing on documents, observations, and semi-structured interviews with civil society leaders, two kinds of opposition coalitions are identified. “Critic negotiators,” emphasizing active engagement and policy research, used the limited participation space opened by authorities to push for reform. “Transgressive resisters,” repudiating the formal consultation process, deployed confrontational tactics and posed more fundamental challenges. This work uses social movement theory to explore coalition resource mobilization, the role of movement entrepreneurs, strategic decision-making, mechanisms linking local and transnational activists, and the dynamics of intra-movement competition.