Correction: An earlier version of this story stated that Feminists for Life opened its doors in 1973. In reality, the organization launched in 1972.

Today, as antiabortion protesters kick off the annual March for Life, they will celebrate some surprising heroines: the suffragists who fought for women’s right to vote. Ironically for some, the centennial of the 19th Amendment to the Constitution falls in a year when many expect the Supreme Court to scale back abortion rights or dismantle Roe v. Wade altogether.

This is not the first time many expected the court to undo abortion rights. In the early 1990s, when the court had eight Republican appointees, it also seemed likely. But the lead-up to what some see as Roe’s inevitable demise feels very different this time. Before, supporters of a “right to life” clashed with proponents of a “right to choose.” This time, both sides claim to be the real supporters of equality for women. The 2020 March for Life is a reminder of how much the terms of the abortion debate have changed. The fate of Roe will probably turn on what the Supreme Court believes is good for American women — and what kinds of evidence and expertise it uses to answer that question.

How did the equality wars begin? For the most part, the early decades of the abortion debate pitted arguments about fetal rights against those about equality and autonomy for women. Antiabortion proponents argued that abortion represented discrimination against unborn children. Abortion rights advocates responded that bans on abortions reflected sex stereotypes and denied women the ability to determine their own futures.

There were some antiabortion advocates who contended that abortion hurt women. Feminists for Life opened its doors in 1972, the year the before the Court decided Roe. And women always played a major role in the antiabortion movement. Grass-roots activism turned homemakers into savvy political operators. As early as the 1970s, professional women, at times, led organizations such as the National Right to Life Committee and March for Life. But for decades, antiabortion feminists did not define their movement’s message or legal agenda. Antiabortion advocates talking about equality tended to focus on fetal rights, not arguments about sex equality.

Why? For some, equality for women was a distraction from the quest for fetal rights. Others simply didn’t buy that women who had abortions were victims. In the late 1980s and early 1990s, even when internal polling showed that voters believed that antiabortion proponents were more anti-woman than the opposition, nothing changed. Operation Rescue carried out clinic blockades that generated famous images of terrified women and screaming protesters. Established antiabortion groups focused on initiatives that seemingly cast women as villains, including a push to outlaw what they called “convenience” abortions.

The 1992 decision Planned Parenthood v. Casey, in which the Supreme Court decided not to overturn Roe, changed this thinking. The plurality opinion stressed that women had made political and economic gains because abortion remained an option. The court also discussed concerns that reversing Roe would damage the institution’s reputation and legitimacy.

Where some saw only a major loss, antiabortion lawyers identified a new path to reversing Roe. What if abortion foes could prove that women didn’t need abortion to maintain political and economic progress? If they could persuade Americans not to support access to legal abortion because they believed it wasn’t necessary, the court might not be quite so worried about a backlash that would damage its reputation. And if the justices could be convinced that abortion hurt women, then the foundation of Roe and Casey would crumble.

This reasoning spawned a focus on equality for women. Theoretically, this new focus might have created common ground between those on opposing sides of the abortion conflict. Some antiabortion feminists agreed with their abortion-supporting counterparts about the need for better protections against pregnancy and sex discrimination. Some also backed paid family leave and improving maternal health care.

But while these shared positions might have spurred a more productive conversation, the issue instead became more polarized.

In the 1990s, antiabortion groups began championing “right to know” laws that required women to hear claims about the risks of abortion. Theoretically, this fit with the idea of equality for women by empowering them to make more educated decisions. Over time, however, these laws led to women hearing more and more contested assertions — some suggesting that abortion caused post-traumatic stress disorder, infertility or a higher risk of cancer. Antiabortion advocates backing these laws had founded research organizations and collected testimonials from women who regretted their experiences — part of a push to persuade women to make what antiabortion advocates saw as the better choice.

Abortion rights advocates labeled these findings as sham science. Antiabortion feminists fired back, saying that the medical establishment — especially the American College of Obstetricians and Gynecologists — was driven by political correctness rather than by science and was leading women astray. Groups such as the ACOG had a majority of abortion rights advocates as members and sometimes submitted amicus briefs supporting abortion rights in court. Antiabortion advocates saw this as proof of a bias that they believed infected much of the medical establishment.

While both sides defined themselves as defenders of women’s equality, they disagreed about what evidence counted in discussing the impact of abortion on women. The debate became intertwined with broader conversations about the difference between science and spin.

Now, with the Supreme Court again poised to make itself heard, polls suggest that a majority of Americans want abortion to remain legal, but the gap between antiabortion and abortion rights activists seems wider than ever. By June, many expect a decision in the most significant abortion case in decades, June Medical Services v. Gee. Court watchers are waiting to see what message any decision will send about the fate of other precedents, Roe first among them. Others focus on the possibility that the court will hold that doctors and clinics can no longer bring constitutional cases on their patients’ behalf, making it much harder for challenges to abortion restrictions to get their day in court. And, of course, there is a chance that the court will undo Roe now.

The clashing visions of equality for women in the case deserve attention. A group of women submitted a brief extensively detailing how access to abortion had empowered them to pursue a career, parent, get an education and determine the course of their lives. Speakers at March for Life, by contrast, will argue that the only path to empowerment lies in rejecting abortion, embracing women’s fertility and demanding that society accept that women can parent while pursuing other opportunities.

The suffragists who inspire activists on both sides of the abortion conflict would certainly be pleased that Americans who can agree on so little celebrate their legacy, but the same reformers might be saddened by the sharp polarization of our politics. We might get much further with equality for women if we could sometimes agree about what it means and focus on common ground, not on our divisions.