Policy Diffusion as a Geographical Expansion of the Scope of Political Conflict: Same-Sex Marriage Bans in the 1990s

Abstract

In 1996, more than half of the states considered legislation banning same-sex marriages. This article examines these events as a geographic expansion of the scope of the conflict rather than as traditional state-centered policy innovation. I argue that the diffusion of same-sex marriage bans was determined by the organized efforts of advocacy coalitions and internal state characteristics rather than by regional diffusion or communication among policy experts. I use state-level data collected from activists, media accounts, and official sources to establish the organized efforts to ban same-sex marriage. I then develop and empirically test a model of policy diffusion to predict both state consideration and adoption of policies banning same-sex marriage. The findings suggest that the diffusion of these policies is best explained by the presence of an organized national campaign by conservative religious groups, the local resources of interest groups, and other internal state characteristics rather than by regional diffusion patterns. I also find that the influence of state characteristics may vary during the policymaking process.