The analysis deals with the effect of constitutional rules on agricultural policy outcomes in a panel of 74 developing and developed countries, observed in the 1955-2005 period. Testable hypotheses are drawn from recent develop in comparative politics that see political institutions as key elements in shaping public policies. We focus the attention on the effect of both broad political reforms – reforms in (and out of) democracy – and on narrow details of democracy, such as electoral rules and forms of government. Using differences-in-differences estimation we find a positive effect of a transition into democracy on agricultural protection. However, the average effect masks substantial heterogeneities across different forms of democracy. Transitions into parliamentary and, especially, proportional democracy – as opposed to presidential and majoritarian – appear to produce the most increase in agricultural protection and support.