Washington ? Billy Graham has been one of the most visible, respected and influential Christians in the world since the 1950s. But he often had a blind spot when it came to politics. Graham was Richard Nixon’s golfing buddy and spiritual adviser. He was there to pray with Nixon after every victory and loss. And Nixon consulted him on everything from his vice presidential pick to the conduct of the Vietnam War.

It must have been a heady experience. “Nixon showed his friendliness to me in many personal ways,” Graham later recalled. “He came to our home on the mountain. He often referred to the pineapple tea my mother served him when he visited her. … In our games of golf together, he was always willing to coach me. … He remembered birthdays.” In Graham’s view, Nixon was “a modest and moral man with spiritual sensitivity.” He “held such noble standards of ethics and morality for the nation.”

Graham was in denial about Watergate until the last. When he finally read through the Watergate tape transcripts — including profanity, political corruption, lying, racism and sexism — Graham remembers becoming physically ill. He said later of Nixon: “I wonder whether I might have exaggerated his spirituality in my own mind.” Graham’s biographer William Martin quotes a close Graham associate who is more blunt: “For the life of me, I honestly believe that after all these years, Billy still has no idea of how badly Nixon snookered him.”

We can now look back on such gullibility with nostalgia. Billy Graham had the alibi of self-deception. But Franklin Graham, Jerry Falwell Jr., Robert Jeffress and Donald Trump’s other evangelical advocates have no such excuse. They have made their political bargain with open eyes. Trump has made profanity an unavoidable part of our political culture. He is in the midst of a gathering corruption scandal that has left close aides under indictment. He tells repeated and obvious lies. He incites ethnic and racial resentment as a political strategy and was caught on tape bragging about sexual assault. Add to this something that could never be said of Nixon: The credible accusation that Trump paid hush money to a porn star to cover up an affair.

And what is Franklin Graham’s reaction? “We certainly don’t hold him up as the pastor of this nation and he is not. But I appreciate the fact that the president does have a concern for Christian values, he does have a concern to protect Christians whether it’s here at home or around the world, and I appreciate the fact that he protects religious liberty and freedom.”

“A concern for Christian values.” I imagine there is considerable presidential stroking behind such a pronouncement — the current equivalent of remembering birthdays and pineapple tea. But Graham’s argument is as crudely political as it gets. Since Trump has delivered the goods on protecting Christians, evangelicals should give him the benefit of every doubt on moral matters, even when such doubts are absurdly transparent ploys.

The level of cynicism here is startling. Some Christian leaders are surrendering the idea that character matters in public life in direct exchange for political benefits to Christians themselves. It is a political maneuver indistinguishable from those performed by business or union lobbyists every day. Only seedier. You scratch my back, I’ll wink at dehumanization and Stormy Daniels. The gag reflex is entirely gone.

From a purely political perspective, the Trump evangelicals are out of their depth. When presented with the binary choice of Hillary Clinton or Donald Trump, I can understand a certain amount of anguish. But that is not a reason to become sycophants, cheerleaders and enablers. Politics sometimes presents difficult choices. But that is not an excuse to be the most easily manipulated group in American politics.

The problem, however, runs deeper. Trump’s court evangelicals have become active participants in the moral deregulation of our political life. Never mind whatever is true, whatever is honorable, whatever is right, whatever is of good repute. Some evangelicals are busy erasing bright lines and destroying moral landmarks. In the process, they are associating evangelicalism with bigotry, selfishness and deception. They are playing a grubby political game for the highest of stakes: the reputation of their faith.

Not long after Watergate broke, a chastened Billy Graham addressed a conference in Switzerland, warning that an evangelist should be careful not “to identify the Gospel with any one particular political program or culture,” and adding, “this has been my own danger.” The danger endures.

— Michael Gerson is a columnist for Washington Post Writers Group.