Rebels rely on the support of their civilian constituency, but often victimize them to enforce compliance. Scholars know relatively little about how rebels strategize violence against civilians in conflicts where the rebel constituency overlaps with the government’s political support base. This gap is problematic because the rebel constituency comprises a diverse group with varying attitudinal and behavioral characteristics. Offering a novel typology of rebel constituency members — loyals, disloyals, fence-sitters, and free-riders—this study examines the impact of rebel constituency support for the government on the rebels' targeting of their civilian constituency. Leveraging an original dataset of the PKK’s coercive acts targeting civilians in Kurdish-majority provinces of Turkey between 2014 and 2019, I proxy rebel constituency support for the government with district-level data on incumbent party victory in the 2014 municipal elections and employ a regression-discontinuity approach. I find that the spatial distribution of loyal and disloyal rebel constituency members is crucial in explaining subnational variations in civilian victimization, specifically who is targeted and where. This study enhances our understanding of rebels' use of coercion to alter their constituencies' political allegiances and calls for greater attention to individual or community-level characteristics of civilians, beyond ethnic or identity-cleavages, in rebel-civilian interactions.