Even in an era of marriage diversity, it remains the most unlikely match: President Trump and his loyal evangelical base. In the compulsively transgressive, foul-mouthed, loser-disdaining, mammon-worshiping billionaire, conservative Christians “have found their dream president,” according to Jerry Falwell Jr.

It is a miracle, of sorts.

In a recent analysis, the Pew Research Center found that more than three-fourths of white evangelical Christians approve of Trump’s job performance, most of them “strongly.” With these evangelicals comprising about a quarter of the electorate, their support is the life jacket preventing Trump from slipping into unrecoverable political depths.

The essence of Trump’s appeal to conservative Christians can be found in his otherwise anodyne commencement speech at Liberty University. “Being an outsider is fine,” Trump said. “Embrace the label.” And then he promised: “As long as I am your president, no one is ever going to stop you from practicing your faith.” Trump presented evangelicals as a group of besieged outsiders, in need of a defender.

This sense of grievance and cultural dispossession — the common ground between The Donald and the faithful — runs deep in evangelical Christian history. Evangelicalism emerged from the periodic mass revivals that have burned across America for 300 years. While defining this version of Christianity is notoriously difficult, it involves (at least) a personal decision to accept God’s grace through faith in Christ and a commitment to live — haltingly, imperfectly — according to his example.

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In the 19th century, evangelicals (particularly of the Northern variety) took leadership in abolitionism and other movements of social reform. But as a modernism based on secular scientific and cultural assumptions took control of institution after institution, evangelicals often found themselves dismissed as anti-intellectual rubes.

The trend culminated at the 1925 Scopes Monkey Trial, in which evolution and H.L. Mencken were pitted against creation and William Jennings Bryan (whom Mencken called “a tin pot pope in the Coca-Cola belt and a brother to the forlorn pastors who belabor half-wits in galvanized iron tabernacles behind the railroad yards”). Never mind that Mencken was racist, anti-Semitic and an advocate of eugenics and that Bryan was the compassionate progenitor of the New Deal. Fundamentalists (a designation adopted by many evangelicals) lost the fundamentalist-modernist controversy, even in their own minds.

After a period of political dormancy — which included discrediting slumber during the civil rights movement — evangelicals returned to defend Christian schools against regulation during the Carter administration. To defend against Supreme Court decisions that put tight limits on school prayer and removed state limits on abortion. To defend against regulatory assaults on religious institutions. Nathan Glazer once termed this a “defensive offensive” — a kind of aggrieved reaction to the perceived aggressions of modernity.

Those who might be understandably confused by the current state of evangelicalism should understand a few things:

First, evangelicals don’t have a body of social teaching equivalent, say, to Catholic social doctrine. Catholics are taught, in essence, that if you want to call yourself pro-life on abortion, you also have to support greater access to health care and oppose the dehumanization of migrants. And vice versa. There is a doctrinal whole that requires a broad and consistent view of social justice. Evangelicals have nothing of the sort. Their agenda often seems indistinguishable from the political movement that currently defends and deploys them, be it Reaganism or Trumpism.

Second, evangelicalism is racially and ethnically homogeneous, which leaves certain views and assumptions unchallenged. The American Catholic Church, in contrast, is one-third Hispanic, which changes the church’s perception of immigrants and their struggles. (Successful evangelical churches in urban areas are now experiencing the same diversity and broadening their social concern.)

Third, without really knowing it, Trump has presented a secular version of evangelical eschatology. When the candidate talked of an America on the brink of destruction, which could be saved only by returning to the certainties of the past, it perfectly fit the evangelical narrative of moral and national decline. Trump speaks the language of decadence and renewal (while exemplifying just one of them).

In the Trump era, evangelicals have gotten a conservative Supreme Court justice for their pains — which is significant. And they have gotten a leader who shows contempt for those who hold them in contempt — which is emotionally satisfying.

The cost? Evangelicals have become loyal to a leader of shockingly low character. They have associated their faith with exclusion and bias. They have become another Washington interest group, striving for advantage rather than seeking the common good. And a movement that should be known for grace is now known for its seething resentments.

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