| Abstract: | Policy diffusion literature generally studies the adoption of similar policies across jurisdictions, but often overlooks how opposing policies or legal constraints may influence the enactment of rigid state constitutional amendments. The current study models the spread of state constitutional amendments designed to prevent future policy change. Using conditional event history analysis on all states from 1999 to 2011 the empirical models analyze the spread of same‐sex marriage prohibitive amendments across the United States. Findings suggest that the nearby adoption of opposing policies encourage state legislatures to introduce prohibitive amendments. The regional diffusion effect suggests that policymakers “protect” their jurisdiction from nearby diffusion forces or seek electoral gains by symbolic protection by committing an already existing policy into the rigid state constitutional framework. Regional policy diffusion may, therefore, be explained by a countermovement mechanism unique to the state constitutional amendment process. This protective strategy among state legislatures and citizens may explain why many policy areas are frequently codified in state constitutions. |
