This paper seeks to identify key factors that drive public or legislative support for the legalization of recreational marijuana across U.S. states by using a panel of annual state-level data from 2013-2018. Existing research has only focused on a few states and it is unclear whether such results are generalizable. This study incorporates a unique set of median voter and special interest variables suggested by earlier economic analysis, as well as relevant research from other disciplines. The opportunity to legalize with a ballot initiative is particularly noteworthy since most states that legalized early did so via a ballot initiative process, rather than through the state legislature. Moreover, because some studies have found evidence of spatial relationships in other public policy decisions, we estimate models explaining the decision to legalize recreational marijuana with a spatial probit procedure, though we find little evidence of spatial dependence in the decision. Our results suggest that the decision is influenced by religiosity, urbanization, the proportion of young people, state and local government expenditures, tobacco company lobbying, and state propensity to use the ballot initiative process.