This study asks: What drives divergent reactions to demographic transformation? This question has grown in salience as the politics of the United States and Western Europe react to the prospect of becoming Majority Minority stateswhere the native constituency of people, defined by race, ethnicity, and/or religion, loses its numerical advantage in the territory of a sovereign state. Relatively little is known about how societies govern such demographic change in the course of global history such that we may anticipate and contextualise policy responses today. To address this question, I undertake a comparative historical analysis of six Majority Minority states-Bahrain (1920-2010), the Hawaiian Kingdom (1840-1900), Mauritius (1830-1880), historic New York State (1830-1880), Singapore (1850-1970), and Trinidad and Tobago (1840-2010). Earlier historical work and contemporary attitudinal analyses have focused on the ways that popular discontent, racism, and xenophobia drive responses. However, I find that that divergent political outcomes are subject to national institutionsspecficially, whether the state equally enfranchises the newcomer population and whether the government's subsequent redefinition of the national identity is inclusive or exclusive.