Criminal violence differs from other conflicts because illegal cartels primarily use violence to eliminate rivals rather than overthrow the state. However, politicians’ ability to influence cartel behavior remains unclear. This article argues that politicians alter the use of violence by setting their jurisdiction’s police enforcement levels, but that cartels can bribe politicians to look the other way. Because cartels are uncertain about politicians’ corruptibility, not every bribe is successful. Following an election, cartels must invest resources into learning politicians’ level of corruption. Cartels only increase their level of violence after successfully bribing political leaders, which implies that local violence levels should increase the longer parties remain in office. The study formalizes this argument and tests its implications using data on homicides and political tenure from Mexico. The results link incumbency to violence and suggest Mexico experiences an additional 948 homicides for each year of increased political tenure after holding an election.