Following the creation of the Alliance for Progress in 1961, several structural reforms were implemented in Latin America in response to the political effects of the Cuban Revolution. Among these, land reform was arguably the most important policy. Using a unique dataset of land expropriations, and a plausible exogenous variation in land concentration, this paper studies the causal effects this policy had on political support for the incumbent party in the central government. In a context where the incumbent was losing political support (and the power of the left wing was rising), municipalities affected by land reform voted by 3-5 percentage points higher for the incumbent than municipalities not affected by this process. Although it did not prevent the first democratically elected Marxist government, land reform decreased the political support for the left wing party. I discuss several theoretical mechanisms that can explain this empirical result.