This article analyzes the constitution of dockworkers’ power and its impact on trade union strategy in recent labor disputes in Chile and Colombia. Dockworkers’ strategic location in the economies of both countries would predict a high degree of shop-floor power among both groups. In practice, however, Colombian dock-workers had far less shop-floor power than their Chilean counterparts, as a result of mitigating social and political factors. Consequently, they developed a strategy this study terms human rights unionism, relying on external allies and lawsuits for leverage, rather than shop-floor action. Dockworkers in Chile, by contrast, adopted a strategy termed class struggle unionism, relying on nationally and internationally coordinated shop-floor action. This article therefore proposes an expanded model of workers’ structural power, incorporating the roles of state and society to better account for power differentials and divergent strategic pathways among workers who share a common position in the economic system.