In 1979, a group of Barry Goldwater campaign veterans, including Paul Weyrich, Richard Viguerie and Howard Phillips, saw an opportunity to recruit social conservatives to the Republican Party. Evangelicals had recently emerged as an important political force - they helped elect one of their own, Democrat Jimmy Carter, to the presidency in 1976 - and Weyrich and his colleagues had a plan to lure these voters to the GOP. To do so, they tapped a charismatic but fairly obscure Baptist televangelist named Jerry Falwell to head the Moral Majority, an organization whose founding marked the beginning of the modern religious right.

The Moral Majority would be replaced by Pat Robertson's Christian Coalition in the late 1980s, which itself gave way to James Dobson's Focus on the Family and various statewide networks in recent years. But Falwell remained relevant, despite the attempts of some embarrassed Republicans to ignore him. Just ask John McCain, who tried to defy the reverend and his movement in 2000, calling Falwell and Robertson "agents of intolerance". His subsequent losses in the Virginia and South Carolina primaries taught him a lesson about the party he hopes to lead, so last year he traveled to Lynchburg, Virginia to give the commencement speech at Falwell's Liberty University. As McCain's humiliating genuflection shows, Falwell and his successors have managed to remake the party in their image.

It's hard to believe now, when evangelicals and fundamentalists make up the most organized bloc in American politics, but before the Moral Majority a person's churchgoing habits didn't tell you much about how they voted, and politicians weren't expected to make lavish displays of their piety. The notion of church/state separation, now widely regarded by Republicans as part of a devious war against Christianity, was a widely shared principle. Falwell himself once denounced preachers who got involved in governance, though not out of devotion to a secular republic: As a committed segregationist, he decried the work of Martin Luther King Jr, saying, "Preachers are not called to be politicians, but to be soul winners."

What changed? The religious right's creation myth holds that Roe v Wade so outraged the faithful that they could no longer sit passively on their pews. As the Columbia University historian Randall Balmer has shown, this is nonsense. The Southern Baptist Convention, Falwell's denomination, was officially pro-choice throughout the 1970s; anti-abortion activism was seen as the province of Catholics, a group then widely despised by fundamentalist Protestants. No, what really galvanized the religious right were Supreme Court rulings stripping whites-only Christian academies, like the one Falwell founded in 1966, of their tax-exempt status. Fervent opposition to abortion, which eventually cemented the alliance between conservative Protestant and Catholics, came later.

Perhaps because of the power he accumulated, or because of the American media's tendency to indulge the far right while marginalising the moderate left, Falwell was able to escape the taint of this history. He would eventually and expediently repent of his opposition to integration, but his general radicalism didn't abate - he famously blamed the carnage of September 11 on "the pagans, and the abortionists, and the feminists, and the gays and the lesbians who are actively trying to make that an alternative lifestyle, the ACLU, People for the American Way, all of them who have tried to secularise America." No matter what he said, though, the weird amnesiac alchemy of American politics ensured that he remained a somewhat acceptable figure, courted by politicians and network TV shows alike.

Towards the end of his life, he even had the awe-inspiring audacity to invoke Martin Luther King Jr as an inspiration. Just last year, I saw Falwell speak at a rally against liberal judges at a black Baptist church in Philadelphia. The room was alive with foot-stomping gospel enthusiasm, and Falwell smiled on the stage as King's rightwing niece Alveda, a frequent guest at conservative conferences, sang "We Shall Overcome". Falwell was one of a series of preachers, both black and white, who summoned the language and imagery of the civil rights movement. Incandescent with righteous outrage, they pledged to triumph over...well, over the very liberal courts whose civil rights rulings propelled Falwell into politics in the first place.

It is evidence of Falwell's triumph that few considered this spectacle anything but ordinary.

Michelle Goldberg is the author of the New York Times bestseller Kingdom Coming: The Rise of Christian Nationalism. She's currently working on a book about the global battle over reproductive rights.

© 2007 The Guardian