White evangelical Protestants, compared to nonreligious and other religious Americans, are the most resistant to civil rights protecting transgender people, including gender affirming health care, inclusive classrooms and sports teams, and access to public facilities such as bathrooms. Evangelical organizations have led political efforts to oppose transgender people and rights based on the belief that that sex/gender is immutable, dichotomous, and created by God. Beyond quantitative surveys and journalistic accounts, we lack systematic qualitative and mixed-methods analyses of the relationship between White evangelicals and the anti-transgender movement. My proposed project fills this gap with research that will culminate in a book manuscript. Using both qualitative and quantitative methods—including analysis of historic and contemporary documents, in-depth interviews and participant observation, and analysis of national survey data, my project will explain how and why White evangelicals oppose transgender rights today in America and how it connects to their political efforts in the past. Understanding these efforts will shed light on the broad relationship between religion and politics in the United States and offer a way for the North American church to hold more complex understandings of people’s beliefs and identities related to sex, gender, and sexuality.