It is common in the study of eugenics to cite structural factors such as racism, misogyny, and – perhaps above all – fear as the doctrine’s causes: fear of population decline, fear of polluted genetic stock, and fear of the undesired subaltern peoples. Although political institutions contain, shape, and limit behavior, they themselves cause nothing. People, or “actors,” in social science language, do. Without a cohort of individuals prepared to lobby for state sterilization laws, to draft them, to present them before state legislatures, and to sign them into law, there would have been no coerced sterilization in America. Many of the same actors were also needed to implement the laws.

In the majority of examples, the key actor in the history of state sterilization laws was the superintendent of homes for the feebleminded. He (and, in one instance, she) naturally needed support, and this support came from sympathetic legislators prepared to place a bill before the legislature and to guide it through the law-making process. As is possible for all bills passed by state legislatures, state governors could veto eugenic sterilization bills. The decision to do so was partly about personal conviction but was mostly about politics: then as now, governors had to weigh the political costs of signing or vetoing a law. The targets of coerced sterilization were in the vast majority of cases poor, powerless, and mostly did not vote, so the incentive structure tilted in favor of approving coerced sterilization laws. It is thus not a surprise that the majority of U.S. states adopted them. Coerced sterilization became politically costly only when articulate, determined, and moneyed interests opposed the sterilization law. Throughout twentieth-century America, this opposition came from the Roman Catholic Church.