Trade union leaders serve dual, seemingly contradictory roles. They must command militant organizations in conflicts with employers. Simultaneously, they must be accountable and democratically responsive to their members. Few unions possess the institutions or leadership to accomplish both. This article analyzes the practices of the International Longshore and Warehouse Union (ILWU), in which effective contract negotiation (including leadership during strikes) and an informed, active rank-and-file democracy are mutually supportive. We offer an alternative to standard accounts of union democracy. While the claims are based on a detailed case study, the theoretical model and its insights hold for labor unions and organizations more broadly.