ObjectiveAlthough the United States 1993 Family and Medical Leave Act is considered meager by international standards, significant variation in family leave policies exists across U.S. states. This article develops a political theory—driven by mobilized interest groups—to explain variation in the duration and pay level of state parental leave policies.MethodsEmploying four different measures of family leave policy, we use ordinary least squares and logit models to test the effects of partisanship, women in the legislature, and evangelical populations on parental leave outcomes.ResultsWe find that states with a pattern of Democratic Party controlled legislatures and high percentages of legislative seats occupied by women see more generous parental leave protections, while states with large populations of evangelical Christians see less generous policies.ConclusionFamily leave policies are the product of a battle between competing visions of the family and the state, shaped by partisanship, gender, and religion.