COLUMBUS, Ohio (AP) — With Election Day closing in, anti-abortion groups seeking to build opposition to a reproductive rights measure in Ohio are messaging heavily around a term for an abortion procedure that was once used later in pregnancy but that hasn't been legal in the U.S. for over 15 years.

In ads, debates and public statements, the opposition campaign and top Republicans have increasingly been referencing “partial-birth abortions” as an imminent threat if voters approve the constitutional amendment on Nov. 7. “Partial-birth abortion” is a non-medical term for a procedure known as dilation and extraction, or D&X, which is already federally prohibited.

“It would allow a partial-birth abortion,” Ohio Gov. Mike DeWine told reporters recently as he explained his opposition to the constitutional amendment, known as Issue 1.

“For many years, in Ohio and in this country, we’ve had a law that said a partial-birth abortion — where the child is partially delivered and then killed and then finally delivered — was illegal in Ohio,” the governor continued. “This constitutional amendment would override that.”

Constitutional scholars say that is not true and that the amendment would not override the existing federal ban if Ohio voters approve it.

“So changing our constitution will not affect in the slightest way the applicability of the federal partial-birth abortion ban,” said Dan Kobil, a law professor at Capital University in Columbus, who supports abortion rights. “It would be a federal crime for a doctor to violate that ban."

That's because the supremacy clause of the U.S. Constitution calls for federal laws to trump state laws, said Jonathan Entin, professor emeritus of law at Case Western Reserve University.

“If the federal law prohibits a particular technique, then that’s going to prevail over a state law that might be inconsistent,” he said.

Ohio is the only state this November where voters will decide whether abortion should be legal. But the debate isn’t happening in isolation. The state has been used as a campaign testing ground by anti-abortion groups after a string of defeats since the U.S. Supreme Court overturned a constitutional right to the procedure. And next year, abortion rights supporters are planning to put the question before voters in several more states, ensuring the issue will be central to races up and down the ballot.

A D&X procedure involved dilating the woman’s cervix, then pulling the fetus through the cervix, feet-first to the neck. The head was then punctured and the skull emptied and compressed to allow the fetus to fit through the dilated cervix. Before the federal ban, it was used for both abortions and miscarriages in the second and third trimesters of pregnancy.

DeWine was serving in the U.S. Senate when the Partial-Birth Abortion Ban Act was passed in 2003. He voted for the prohibition, which declared a “moral, medical, and ethical consensus” that the procedure was “gruesome and inhumane.” President George W. Bush signed the measure into law with DeWine at his side.

The ban was largely on hold while a constitutional challenge played out. The U.S. Supreme Court in 2007 rejected arguments against the law, upholding its application across all 50 states.

Asked why the governor suggested a federal law he supported would not apply if Ohio changes its constitution, spokesman Dan Tierney said DeWine bases his position on provisions of the U.S. Constitution that prevent the federal government from regulating conduct that has no effect on interstate commerce. Kobil acknowledged that argument, but said it’s “almost certain to fail” if tested, given that the Supreme Court already declared the ban constitutional.

DeWine isn't the only top elected Republican in the state to warn that the procedure would be revived if the amendment passes on Nov. 7.

In a memo earlier this month, Republican Attorney General Dave Yost said the state’s laws outlawing abortions through D&X and another procedure, non-intact dilation and evacuation, or D&E, the most common second trimester method, “would both be invalidated and these abortions would be permitted” if the amendment passes. The Ohio Senate’s Republican supermajority passed a resolution saying something similar.

Entin, of Case Western, said “to the extent that the Ohio laws he’s discussed are also covered by the federal law, it doesn’t matter,” because federally banned procedures would remain illegal.

Kelsey Pritchard, director of state public affairs for Susan B. Anthony Pro-Life America, whose political arm is a major funder of the campaign opposing the amendment, said the federal ban “lacks enforcement” under a Biden Administration she described as “extreme pro-abortion.”

“If it's not being enforced, if there's no teeth to it, then the protections need to happen at the state level,” argued spokesperson Amy Natoce of Protect Women Ohio, the Issue 1 opposition campaign. “Of course, if Issue 1 passed, we won't have those protections.”

Mae Winchester, a Cleveland-based maternal fetal medicine specialist, said use of the term in the campaign messaging over the amendment is misleading.

“‘Partial-birth abortion’ is a made-up term that only serves to create confusion and stigmatize abortion later in pregnancy,” she said. “It’s not a procedure that’s described anywhere in medical literature, and so it’s not considered a medical term or even an actual medical procedure.”

Ohio passed the nation's first ban on what its lawmakers then dubbed “partial birth feticide” in 1995, just three years after Ohio physician Martin Haskell debuted the D&X procedure during an abortion practitioners conference. He touted it as a way to avoid an overnight hospital stay and as safer and less painful for women than other methods.

Protect Women Ohio has invoked Haskell’s legacy in one of its ads. It shows an image of Haskell and describes the procedure he pioneered as “painful for the mother and the baby.” The voiceover then calls for a no vote on the amendment “so people like Dr. Haskell can't perform painful ‘late-term’ abortions.”

The spot doesn’t note the distinction between “partial-birth” and “late-term” abortions — both non-medical terms coined by anti-abortion advocates — nor reference the federal ban.

Mike Gonidakis, president of Ohio Right to Life, said because of protections provided to individuals and abortion providers in the amendment, “The ad withstands any scrutiny.”

Haskell retired from active practice two years ago. He declined comment. But he has donated to the main group supporting the constitutional amendment, Ohioans United for Reproductive Rights.

Pro-Choice Ohio Executive Director Kellie Copeland called talk of “late-term” and “partial-birth” abortions a scare tactic.

“Issue 1 allows for clear restrictions on abortion after viability that protect patients’ health and safety,” she said. “These situations, when a woman needs an abortion later in pregnancy, are incredibly rare and heartbreaking for families.”

Ohio hasn’t had an abortion of any type performed after 25 weeks’ gestation since 2018 and only four have been recorded since 2013, according to statistics compiled by the state Health Department. Abortions between 21 and 24 weeks’ gestation, a span that encompasses the outside limit of Ohio’s current law, totaled 576, or 0.6% of the total, over that time.

Pritchard, of Susan B. Anthony Pro-Life America, attributed the low numbers to the state's existing abortion restrictions.