Previous research emphasizes the importance of path dependence for sustainable energy transitions, but their strategic nature is frequently overlooked. We examine formally how exogenous shocks, such as changes in international energy prices, interact with positive reinforcement factors, such as the growing strength of the renewables advocacy coalition. We find that political competition modifies the effect of path dependence on policy and outcomes. Specifically, while “green” governments can use positive reinforcement mechanisms to lock in policy commitments (by creating green constituencies), “brown” governments strategically underprovide public support for renewable energy (to avoid creating green constituencies). The effect of positive reinforcement also decreases with international energy prices. Our empirical analysis shows that (1) political competition conditions the policy response to exogenous shocks and market failures, while (2) governments strategically exploit path dependence for political gain.