By the time of the Civil War, evangelical churches were so dominant, Kidd writes, that they represented a de facto establishment. But the issue of slavery tore the Northern and Southern churches apart, and divided black from white churches. Kidd tells us evangelicals would never again reach the same level of cohesion that they did before the 1840s. Still, white evangelicals remained the de facto establishment in both the North and South, making laws on such things as prayer in the public schools.

In fact, the first real split in evangelicalism came in the Northern churches at the end of the century over the issues of theology and Darwinian evolution. Kidd describes the doctrinal splits, but says, “Promoting anti-evolution laws was one of the most misguided evangelical ventures ever,” and the Scopes trial of 1925 “illustrated the temptations of media access, establishment politics and celebrity politicians in evangelical history.” The trial, he writes, “was a major precedent for the crisis of politicization that bedevils evangelical Christianity today.”

Interestingly, Kidd traces what he calls the crisis of the movement to the 1940s, when Billy Graham and many other preachers blended their gospel with anti-Communism. The turning point, he says, came when Graham made an alliance with President Eisenhower, and evangelicals began to conflate pollical power and access to Republican leaders with the advancement of God’s kingdom. Kidd describes the Republican efforts to woo evangelicals while President Johnson’s civil rights acts were turning white Southerners against him. Throughout the book, Kidd does a good job of including the perspectives of black clergymen. However, he, like many other evangelicals, often equates “evangelicals” with “Christians,” and negates the role Northern white Catholics and mainline Protestants played in the civil rights movement.

He continues his historical narrative through the rise of the Christian right (or what he calls “Republican insider evangelicals”), plus the “conservative resurgence” in the Southern Baptist Convention. Only in his last pages does he get to the election of Donald Trump, and after all he has said about the corrupting effects of political power on a religious community, the coda is disappointing. He recites the familiar excuses: Evangelicals voted against Hillary Clinton rather than for Donald Trump; among Christians in politics, the media care only about evangelicals; polling doesn’t differentiate between nominal evangelicals and those who hold to traditional beliefs, etc. He admits that evangelical fealty to the Republican Party is real and has done considerable damage to the movement, but he insists that evangelicals should not be defined by the 81 percent because being a real evangelical entails conversion, devotion to an infallible Bible and to God’s discernible presence on earth. But since polls show that evangelicals who attended church frequently voted for Trump at much the same rate as nominal evangelicals, he is left with no explanation for why so many evangelicals voted for an adulterer who boasts about his sexual conquests.

Ben Howe is not the scholar Kidd is, but his book comes closer to an explanation; for, unlike Kidd, Howe was a conservative activist who went through a change of heart during the 2016 primaries. A writer, podcaster and filmmaker, he grew up in what he describes as an “ideal” evangelical family. As the family moved about, he went to W. A. Criswell’s church in Dallas and later to Jerry Falwell Sr.’s church in Lynchburg, Va. The two pastors were fundamentalists, heavily involved with politics and, as a boy, Howe supported the Moral Majority. Later, he had great hopes when George W. Bush was elected. He liked the idea of “compassionate conservatism,” and he also liked the president’s “moral clarity” when, after 9/11, he told America’s allies that they had to be either for the United States or for the terrorists. Many evangelicals, Howe writes, had come to believe that the cultural tide was shifting, putting the idea of a Christian nation at the forefront of popular conservative thinking.