Many studies highlight the critical roles of political parties in enhancing autocratic durability, mainly emphasizing mechanisms related to elite cohesion. The role of a mass party organization in stabilizing autocracies, though well recognized, has received relatively less emphasis. This article argues that the import of mass organization on autocratic durability is likely to vary with autocratic regime type and be greatest in competitive authoritarian regimes. I then exploit unusual survey data and an original data set containing information on 18,037 regime-affiliated "Communal Councils" to examine the effects of a regime-affiliated mass organization on the incumbent vote in Venezuela. The formation of Communal Councils exerted a large effect on incumbent support but the strength of this effect varied depending on whether Councils were located in communities receiving high levels of material resources. These findings suggest that mass organization can greatly enhance competitive authoritarian durability but must be backed by patronage to be effective.