Reassessing Madison's Diversity Hypothesis: The Case of Same-Sex Marriage


Sean Nicholson-Crotty is assistant professor of political science, University of Missouri–Columbia, Columbia, MO 65211.


Scholars have long suggested that population diversity should serve as a check on majority tyranny, but empirical evidence for this diversity hypothesis is inconclusive. This essay suggests that mixed findings arise because of the way in which scholars have translated Madisonian writings into statistical tests. It argues that the Federalist papers actually suggest an interactive relationship, where diversity moderates the effectiveness of representative institutions in protecting minority rights, rather than a direct relationship between population homogeneity and repression. The article tests for this moderating effect via a mixed methods approach, which includes a quantitative analysis of the passage of same-sex marriage bans in the American states, as well as a qualitative examination of legislative activity in four states.