Electoral autocrats are often characterized as hegemonic. Despite this, opposition parties sometimes win elections and challenge their rule. How do opposition parties build support? How does local control - who wins elected local office - affect electoral strategies and hence political competition? I argue that local control defines the strategies of incumbents and opposition parties use to compete for votes. When incumbents retain local control, local capacity makes it easier for incumbents to credibly threaten to sanction opposition support. However, when opposition parties win local control, they gain unprecedented opportunities to use distributive politics to win support. Opposition control therefore increases opposition support. I test this argument using administrative data and interviews from Tanzania.  I find that electoral autocrats are only able to mobilize local capacity if they retain local control. When opposition parties win control, they even access to services and improve local governance. I show that they do so, despite receiving lower central transfers, by investing in local capacity to maintain their autonomy from the center.  I show the survival and spread of opposition support is conditional on local control. This theory has important implications for prevailing understandings of regime durability, opposition parties and decentralization.