If Pope Francis was aware for years that a prominent American cardinal was a sexual abuser but failed to punish him, we would think every Roman Catholic, liberal or conservative, would want to know that.

The allegation may well amount to nothing. It is included in a hyperventilating 11-page letter, full of personal attacks, by a former Vatican diplomat who makes clear his disgust for the entire progressive wing of the church.

EDITORIAL

The writer of the letter, Archbishop Carlo Maria Vigano, offers no evidence to back up his allegation; and he himself, ironically, once tried to quash an investigation into accusations that another prelate, in the St. Paul-Minneapolis Archdiocese, had engaged in similar sexual misconduct.

But Vigano is no marginal figure within the church, and conservative bishops are defending him. Making matters worse, Pope Francis has declined to refute the accusation directly, saying that reporters have “the sufficient journalistic ability” to size up the letter for themselves. Putting the matter in the hands of reporters, he said, is “an act of trust.”

Well, then, trust us: Francis sincerely may believe that Vigano’s letter is nothing but a hatchet job to which it would be beneath his dignity to respond, but he should.

And an independent review would not be an overreaction. The stakes are too high.

At a time when the Catholic Church continues to be embroiled in scandals of sexual abuse and cover-ups by priests and bishops, the Vatican can’t afford to fail to respond to such a high-level attack on the integrity of the pope himself.

Just two weeks ago, a grand jury found that 301 “predator priests” had sexually molested more than 1,000 children in six Pennsylvania dioceses, over decades. The state’s attorney general, who led the grand jury investigation, said the alleged cover-up stretched “all the way to the Vatican.”

On the line is the Catholic Church’s broader mission and identity. Vigano’s letter, released last Saturday, clearly was designed to undermine the authority of a relatively liberal pope who has taken particular progressive views on such matters as divorce and remarriage, homosexuality, economics and social justice and immigration.

Cardinal Blase Cupich of Chicago, who also comes under attack in Vigano’s letter, told an NBC5 reporter that the heart of the problem is “a small group of insurgents who have not liked Pope Francis from the very beginning. They don’t like that he’s talking about the environment, or the poor or migrants.”

Vigano contends the pope knew for years — long before it became public knowledge this summer — that Cardinal Theodore McCarrick, formerly the archbishop of Washington, D.C., had sexually abused seminarians. The pope did nothing about it, Vigano contends, and even relied on McCarrick’s guidance in choosing other American church leaders, including Cupich.

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Cupich, who says he knew nothing of McCarrick’s misconduct, dismisses the notion that he owes his job to the disgraced cardinal. Cupich points out that he was promoted by three different popes and never needed any one person to be his advocate.

Vigano’s letter is a polemic, and so it’s not to be trusted. We are reminded of the crazy screeds against President Barack Obama that once were common on right-wing websites.

Vigano ropes in every liberal foe, and veers off into the harshest ideology. Particularly offensive is his suggestion — based only on scandals within the unique and insular institution of the church — that gay men in general are more likely than heterosexual men to abuse children. That is a bigoted slur. Nothing in credible, independent research supports such a view.

The antidote to slurs is facts. If Pope Francis, whom we have admired for generally having his priorities right, has been unfairly accused by Vigano, he should respond by cooperating fully in revealing the true facts.

In the same way, we agree with Illinois Attorney General Lisa Madigan that the church in the United States has yet to come clean fully about past abuse. As Madigan wrote this week in the Sun-Times, the church should open its “secret files” for independent review.

Pope Francis says he won’t say “a word” about Vigano’s letter. We wish he would.

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