This paper aims to explain the different political trajectories and identities of two sets of industrial workers in the city of Lyon, France during the years immediately preceding the first World War. Silk workers supported reformist socialist parties while metalworkers were pillars of the revolutionary syndicalist current that dominated the prewar CGT. Unlike base and superstructure models or political autonomy explanations, it is argued that the particular industrial structures and social relations within each industry interacted with local and national political opportunity structures in ways that rendered some strategies and forms of collective action more efficacious than others. The programs and strategies proposed by revolutionary syndicalism matched the conditions of metalworkers and attracted their support, while reformist socialism struck a similar chord with silk workers resulting in similar results.