At the heart of many of today’s most pressing U.S. religious liberty concerns is the fallout from the sexual revolution decades ago, said one author on the subject at a recent conference.

Mary Eberstadt, a senior fellow at the Ethics and Public Policy Center, argued that while atheistic Communism failed in Russia and Eastern Europe, a key error persists today in the form of an intolerant secularism rooted in the sexual revolution.

The “anthropological error” at the heart of Communism, “the notion that man can be man without religious liberty lives on with a vengeance now,” Eberstadt said at a conference in Washington, D.C. on March 17.

“In an unforeseen turn that is not only nationwide but cross-civilizational, religious liberty today appears more precarious in the United States than at any time since the American Founding,” she added.

The Catholic University of America hosted the conference on human ecology, celebrating 125 years of the first modern social encyclical Rerum Novarum. It drew clergy and business leaders from across the U.S. to discuss how businesses can better apply principles of Catholic social teaching to their practices.

Human ecology was the focus of the second part of the conference. Eberstadt’s talk was on “religious liberty vs. the sexual revolution” and the profound implications this fight has for the poor and the vulnerable in the U.S.

Eberstadt is the author of the 2012 book “Adam and Eve after the Pill: Paradoxes of the Sexual Revolution.”

In her talk, she said that secularist forces are trying to close down or de-Christianize religious charities because they won’t comply with their demands for access to contraception and abortion, rooted in the sexual revolution.

If these activists succeed, she added, the consequences will be disastrous for the poor.

This fight is seen most clearly in the administration’s contraception mandate, Eberstadt said. The administration’s “absolutism” in insisting that employers provide contraception coverage for employees — and that religious charities provide it indirectly against their conscience — has led to hundreds of lawsuits, diverting resources away from helping the needy toward legal fees.

The Little Sisters of the Poor, the most prominent plaintiff in these lawsuits, should have won the compassion of everyone in their fight to stay open, Eberstadt said. Their mission of helping the poor elderly “can soften the hardest heart” and yet “even among other people engaged in full-time charity work, the Little Sisters are spoken of with harsh tones.”

“From the point of view of sheer public relations, taking on the Little Sisters of the Poor ought to have been the political equivalent of slapping babies,” she continued, yet the administration is opposing them in court.

“Nothing stopped an American government animated by secularist progressivism from trying to make even the Little Sisters of the Poor knuckle under to whatever is being demanded today in the name of the sexual revolution,” she said.

She gave other examples of this intolerance. The American Civil Liberties Union is suing Catholic hospitals, as well as immigration services of the U.S. Bishops Conference, for not providing abortions. The National Abortion Rights Action League has sponsored legislation to force pro-life pregnancy centers in California to tell patients about abortion and contraceptive options.

These groups may just claim that they are “pro-choice” and in favor of women’s access to these products and procedures, but “something deeper is afoot,” Eberstadt said. These antagonists are “not only despisers,” she added, but “they are, and act like, affiliates of a rival faith.”

This “faith,” is the belief that an autonomous individual should have access to sex, contraception, and abortion and that no entity, including religious charities, should deny them this right.

If these forces win and religious charities must close, the cost would be steep, particularly to the poor people these charities serve, Eberstadt continued. They “cannot be replaced, not overnight, not by government agencies,” she insisted, and their particular love of the poor rooted in Christianity cannot be replicated by the state.

“How is disrupting these supply lines even remotely in the interest of public humanity?” she asked.

How can Catholics respond to these attacks? We must go on the offensive, the speaker stressed. “We need to point out that people who attack charities,” she said, “are subverting the public good.”

“It’s wrong to lay siege to pregnancy centers,” she said of efforts to make pro-life pregnancy centers tell clients about abortion options. “It is wrong to hold desperate immigrants hostage at the Southern border” to comply with secularist demands of access to abortion contraception, she said of the ACLU lawsuits against the U.S. Bishops Conference.

“The attacks on religious charities prove that they do not stand on the high ground,” she said. One faith is “hurting the poor. The other side is doing the opposite,” she concluded.