Mary Ziegler is the Stearns Weaver Miller professor at Florida State University College of Law.

Surrounded by other like-minded physicians and nurses, Shani Meck, a Flowood, Miss., obstetrician, announces her support for the “personhood” amendment during a news conference in Jackson, Miss., on Nov. 3, 2011. (Rogelio V. Solis/AP)

States seem to be competing to pass the most restrictive abortion legislation possible. Gov. Phil Bryant (R) signed Mississippi’s 15-week ban Monday. Not to be outdone, the Kentucky House passed a prohibition on abortions after 11 weeks. Iowa lawmakers are considering a ban once doctors can detect a fetal heartbeat. And the South Carolina Senate is preparing to debate a personhood measure — one that sponsors admit would outlaw all abortions, as well as at least some forms of contraception.

These laws demonstrate the growth of a new personhood movement, a wing of the antiabortion movement committed to more sweeping restrictions than ever before. For years, personhood proposals seemed unconstitutional and unpopular with voters uncomfortable with absolute bans. Even other abortion foes dismissed the personhood movement as a dangerous distraction. But the prospect of new judicial nominations and a transformed Republican Party may have finally given personhood proponents the ingredients to succeed.

In some ways, all abortion foes believe in personhood. In the 1960s, after states began to change laws restricting abortion access, local groups, many of them connected to nearby Catholic dioceses, began to organize. These antiabortion groups made a single constitutional argument: Biological evidence proved that the unborn child was a person. Because people have rights to due process and equal protection of the law, abortion would violate the rights of the unborn child.

After Roe v. Wade rejected this argument and legalized abortion, the antiabortion movement focused on enacting a constitutional amendment recognizing fetal personhood. But over time, leaders of larger antiabortion groups realized that such a strategy was a long shot, given the difficulties of amending the Constitution and the lack of popular support for such a sweeping abortion ban.

So instead of trying to ban abortion, antiabortion proponents decided to champion more modest laws limiting access, aiming to reduce the number of abortions rather than outlawing the procedure outright.

In the post-Roe period, antiabortion proponents began to align firmly with the GOP. Up to that point, the abortion issue had divided both parties, and prominent Democrats like Joe Biden and Thomas Eagleton were antiabortion. By the time Ronald Reagan launched his 1980 presidential run, however, the Republican Party seemed friendlier to antiabortion proponents.

Working within one party also promised abortion foes influence over the selection of new Supreme Court justices when Republicans were in power. If the Court gradually upheld more abortion regulations, such decisions would set the stage to overrule Roe and return the matter to the states.

This partisan and legislative strategy has delivered some results. Starting with President Reagan, Republicans have made eight of the last 12 Supreme Court appointments, including five of the justices on the bench. Although the Court has not overruled Roe, it has scaled back on the protection of abortion rights, and has allowed states to pass nearly 1,200 abortion restrictions since 1973.

Significantly, 30 percent of those restrictions have come in the past seven years. When conservative Republicans took over many state legislatures following the 2010 election, they moved quickly to enact policies right out of the incrementalism playbook: laws that would reduce the abortion rate but stop well short of an outright ban of the procedure.

Even as abortion foes pushed these incremental measures with increasing success, the personhood movement continued to lurk, dividing the antiabortion community. Personhood proponents saw incrementalism as unprincipled. It justified fetal killing for reasons of political expediency and made the antiabortion movement too dependent on the GOP.

For decades, their complaints fell on deaf ears, as the incrementalists had the upper hand. Groups like National Right to Life Committee (NRLC) and Americans United for Life (AUL) steadfastly devised laws that would chip away at Roe, including the proposals President Trump has advocated in the White House, like fetal-pain laws and regulations defunding Planned Parenthood.

Yet personhood advocates remained dissatisfied with incrementalism. A move in the 2000s proved to be the last straw, propelling them to attempt to upend the abortion debate. Mainstream antiabortion organizations had spent more than a decade prioritizing policies to outlaw “partial birth abortion,” a procedure by which a fetus was removed intact. This campaign was politically potent, because it focused debate on controversial late-term abortions and directed attention to fetal life rather than women’s rights. The chances of political success aside, personhood advocates found the strategy offensive because it did not stop abortion and allowed for women to terminate pregnancies using other methods.

In 2008, activists successfully put a personhood proposal on the Colorado ballot. Over the next four years, similar efforts began nationwide. These efforts failed spectacularly. Even Mississippi, a state favorable to almost all abortion regulations, rejected personhood.

And personhood proposals are probably unconstitutional as well as unpopular. Since 1992, when the justices decided Planned Parenthood of Southeastern Pennsylvania v. Casey, the Supreme Court has struck down abortion regulations if they unduly burden women’s access to abortion. Personhood laws obviously run afoul of this standard — most of them ban all abortions at a certain point in pregnancy (if they do not outlaw abortion altogether).

But these obstacles have not dissuaded personhood proponents. They continue to push personhood measures, and they may finally be gaining ground — at least within the GOP.

Why? Today’s personhood advocates are more politically astute than their predecessors. Originally, personhood proponents talked more about religious principles than political tactics. The new personhood activists, however, have mixed political strategy and ideology.

In Georgia, for example, Dan Becker, the former head of an NRLC affiliate, argued that the GOP needed the antiabortion movement at least as much as abortion opponents needed a partnership with the Republican Party. This realization enabled the movement to take a hard line: Georgia antiabortion proponents have refused to endorse candidates unless they supported a complete abortion ban — with no exceptions even in cases of rape or a threat to a woman’s life. Most leading Georgia Republicans have acquiesced.

Personhood proponents may also soon stand a better chance in the Supreme Court. Many expect Justice Anthony M. Kennedy to retire in June. Kennedy often casts the deciding vote in abortion cases. If Trump selects a more conservative replacement, the Court could uphold more restrictive abortion laws.

And Trump may nominate a different brand of justice to the Supreme Court. After the failed nomination of Robert Bork in 1987, Republican presidents often avoided candidates who might alienate swing voters or fail to get enough support in Congress. Trump, by contrast, seems intent on rewriting the rules. It is not unthinkable that he will nominate judges who would be sympathetic to personhood proposals (if he has not done so already).

Personhood proponents could also benefit from Trump’s takeover of the GOP. To some GOP insiders, Trump’s rise shows that candidates win by taking extreme positions and energizing the party’s base. Personhood proposals are extreme, but some of the Republicans who pattern their careers after Trump may not care — or might even see it as a positive. As the Republican Party moves in this Trumpian direction, personhood proponents may find an increasing number of allies.

Trump has spawned a civil war in the GOP between his disciples and the Republican establishment. The antiabortion movement is experiencing a similar battle between personhood proponents and incrementalists.

If the personhood movement wins this battle, it may not be all good news for abortion opponents. Voters still don’t like abortion bans. Just as Trump may not help the GOP in the long term, personhood might hurt the antiabortion movement.

But personhood leaders aren’t focused on popular opinion — they hope to take over the GOP and influence the Supreme Court. With enough Trump-nominated justices on the bench, anything is possible.

Vice President Pence predicted legal abortion would end in our time. The reemergence of the personhood movement makes it harder than ever to know if Pence is right.