Evangelicals, the mainline and politics
American Protestantism splits between liberal "mainline" churches and conservative evangelicals, who become a major political force from the 1970s while the mainline steadily shrinks.
- Fundamentalism and American Culture — George M. Marsden, Oxford University Press (1980)
- The Evangelicals: The Struggle to Shape America — Frances FitzGerald, Simon & Schuster (2017)
- A History of Christianity in the United States and Canada — Mark A. Noll, Eerdmans (1992)
- Religious Landscape Study: Executive Summary — Pew Research Center (2025)
- Voting Patterns in the 2024 Election — Pew Research Center, Pew Research Center (2025)
- America's Pastor: Billy Graham and the Shaping of a Nation — Grant Wacker, Harvard University Press (2014)
In the 1910s and 1920s American Protestants fought over evolution, the historical reliability of the Bible and liberal theology. “Fundamentalists” lost the battle for control of the big northern denominations, and the 1925 Scopes “monkey trial” in Tennessee made them a national joke. They withdrew to build their own colleges, radio programmes and churches, while the “mainline” churches, Methodist, Presbyterian, Episcopal, Lutheran and others, set the tone of American public religion.
- Fundamentalism and American Culture — George M. Marsden, Oxford University Press (1980)
- A History of Christianity in the United States and Canada — Mark A. Noll, Eerdmans (1992)
From the 1940s a new generation calling itself “evangelical”, led above all by the evangelist Billy Graham, reached back into the mainstream. After the sexual revolution, the 1973 Roe v. Wade decision and school-prayer rulings, preachers like Jerry Falwell founded the Moral Majority in 1979, and white evangelicals became a core of the Republican coalition. About eight in ten white evangelical voters backed Donald Trump in both 2020 and 2024, according to Pew.
- The Evangelicals: The Struggle to Shape America — Frances FitzGerald, Simon & Schuster (2017)
- Voting Patterns in the 2024 Election — Pew Research Center, Pew Research Center (2025)
- America's Pastor: Billy Graham and the Shaping of a Nation — Grant Wacker, Harvard University Press (2014)
Meanwhile the mainline churches declined. In Pew’s surveys, mainline Protestants fell from 18% of American adults in 2007 to 11% in 2023–24, and evangelicals from 26% to 23%, as more Americans left religion altogether; Protestants of all kinds are now about 40% of US adults.
- Religious Landscape Study: Executive Summary — Pew Research Center (2025)
Christians must defend unborn life, religious freedom, marriage and the family in public, and the rise of evangelical political engagement since the 1970s was a response to a secularising culture that pushed believers out.
- The Evangelicals: The Struggle to Shape America — Frances FitzGerald, Simon & Schuster (2017)
- Fundamentalism and American Culture — George M. Marsden, Oxford University Press (1980)
Many Protestants, evangelical and mainline, argue that close alliance with one party has traded the gospel for power and damaged the church's witness, especially among the young, and point to the long tradition of Black and progressive Protestant activism for justice.
- The Evangelicals: The Struggle to Shape America — Frances FitzGerald, Simon & Schuster (2017)
- A History of Christianity in the United States and Canada — Mark A. Noll, Eerdmans (1992)
Why it matters today
In the US, "evangelical" is now often heard as a political label, and many evangelicals who do not share the politics feel misrepresented, especially Black, Latino and Asian evangelicals and those outside America. Mainline churches, which once defined American Protestantism, have shrunk sharply. How faith should relate to political power is one of the most painful arguments among Protestants.