Introduction This article investigates how severe organizational fragmentation within Indonesia’s labor movement – widely regarded as a structural barrier to electoral success – was managed in the 2019 legislative election, and under what conditions cross-union cooperation can emerge and sustain electoral coordination. Existing scholarship consistently links labor’s electoral marginalization to fragmentation, restrictive electoral institution, and the absence of a pro-labor party. The electoral victory of Obon Tabroni, a labor candidate from the Federation of Indonesian Metal Workers Union (FSPMI), challenges this dominant expectation. Methods The study employs a qualitative process-tracing design, combining documentary analysis of official electoral data from the General Election Commission (KPU) and labor organization records from the Ministry of Labor with in-depth interviews with union leaders and labor activist. Results Focusing on Bekasi, a labor-dense industrial hub, the findings identify a clear mechanism: fragmentation produces “derby” dynamics in which multiple labor candidates compete within the same constituencies, leading to vote splitting intensified by Indonesia’s open-list proportional representation system. However, the case also demonstrates that fragmentation can be temporarily neutralized through instrumental cross-union coordination that concentrates labor votes behind a single candidate. Discussion Extending Baccaro and Howell’s framework, the article argues that labor agency under fragmented institutional conditions operates through flexible, ad-hoc coalition-building rather than structural unification. Cooperation becomes viable when supported by sectoral commonality, shared historical trajectories, and respected bridging figures. A key limitation is that the observed coordination remains localized and personalized, limiting broader generalization.
Sulaksono et al. (Thu,) studied this question.