Thesis advisor: Donald Hafner / There is perhaps no issue more controversial in the so-called American culture war than that of gay marriage. In the last five years, four states have legalized same-sex marriages and several more appear poised to follow suit. This paper creates an analytical framework with which to evaluate the chances of successful gay marriage initiatives in any given state. Demographics, political institutions, and state-specific variables make up the three parts of the framework, which is then applied to three case studies in which gay marriage has already been addressed: Massachusetts, Vermont, and California. A fourth case, Maine, serves as a prediction state to test the validity of the framework. The paper’s conclusions indicate that, in the current political and cultural domain, there is a set of factors that tend to promote the legalization of gay marriage. The demographics of a population need to be such that they qualify as a “tolerant citizenry,” people who are hesitatingly accepting of gay marriage and can be persuaded to support that legalization. On the political side, a positive evaluation of gay marriage by the state supreme court that then passes on responsibility to the state legislature is the most conducive to legalization. The court provides the constitutional and legal grounds for gay marriage, while the legislature acts as an intermediary between the justices and the wider population. Finally, states in which the constitutions are difficult to amend, and which amendment procedures are controlled by the legislature, are the most likely to legalize gay marriage. The application of the framework to the three case studies illustrates this complex process. / Thesis (BA) — Boston College, 2009. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Political Science Honors Program. / Discipline: Political Science.