From holding up Loretta Lynch’s confirmation as Attorney General and a bill to help victims of sex trafficking to threatening to blow up a carefully calibrated bipartisan agreement on a number of important health policy fixes, it seems there’s no end to the trouble caused by this amendment from hell.

It’s no secret that the Hyde Amendment — to ban federal funding of abortions for low-income women in the Medicaid program — was introduced by pro-life Catholic Congressman Henry Hyde in the mid-1970s and has plagued appropriations bills ever since. But what’s not as well known is the backstage role that the Catholic Church played in its creation.

In fact, without the church, there might not be a Hyde Amendment.

Henry Hyde was a first-term congressman from Illinois when he introduced the amendment in June of 1976. The fledgling anti-abortion movement had been trying desperately since Roe v. Wade three years earlier to get Congress to pass a “Human Life Amendment” to ban abortion, but wasn’t getting anywhere.

The amendment took everyone by surprise, and represented a whole new tactic. Instead of banning abortion outright, opponents would seek to chip away at access by any means available. As Hyde himself famously said:

“I certainly would like to prevent, if I could legally, anybody having an abortion, a rich woman, a middle-class woman, or a poor woman. Unfortunately, the only vehicle available is the … Medicaid bill.”

The bill passed the House but ran into opposition in the Senate. But with elections looming and abortion already a contentious issue in the presidential race, neither chamber of Congress wanted a drawn-out fight. So the Senate acquiesced—with an exception if a women’s life was in danger—because it expected the Supreme Court to strike down the Medicaid funding restriction in two pending state cases.

But when the Supreme Court upheld the restrictions and Hyde reintroduced the amendment in 1977, an epic six-month battle broke out that paralyzed Congress. The Senate dug in and sought to lessen the impact of the ban by allowing “medically necessary” abortions, as well as abortions for rape and incest. Leading the charge for the most restrictive form of the amendment — with no exemptions whatsoever — was Mark Gallagher, the lobbyist for the National Committee for a Human Life Amendment.

The NCHLA was created in 1974 by the U.S. Conference of Catholic Bishops after it lost control of the National Right to Life Committee, which it also created, to a group of Catholic and Protestant anti-abortion leaders who were concerned that the bishops’ involvement hampered anti-abortion efforts. The National Right to Life Committee had attracted millions of members since Roe, but it didn’t have any lobbying clout on the Hill. The NCHLA was the only national anti-abortion organization that “possessed demonstrable political power and expertise,” said Frederick Jaffe, Barbara Lindheim and Philip Lee in their book “Abortion Politics.”

Gallagher and Hyde worked hand-in-glove during the negotiations. The New York Times reported that Gallagher “[made] his unofficial home on Capitol Hill in the office of Representative Henry Hyde” from June to December 1977, when there were 25 roll-call votes on the Hyde Amendment. “Innumerable sessions were held by conferees representing the two houses, and endless hours were consumed with arguments over the relative merits of terms like ‘serious’ versus ‘severe’ … and ‘forced rape’ versus ‘rape’,” notes “Abortion Politics.”

All eyes were on Gallagher. “Every time the Senate conferees make a compromise offer, Mr. Gallagher quietly walks to the conference table to tell a staff aid to the 11 House conferees whether the proposal is acceptable to the bishops. His recommendations invariably are followed,” the New York Times reported, noting that eight of the 11 House conferees were Catholic.