Supporters of a South Dakota abortion rights initiative submitted far more signatures than required Wednesday to make the ballot this fall. But its outcome is unclear in the conservative state, where Republican lawmakers strongly oppose the measure and a major abortion rights advocate doesn’t support it.

The effort echoes similar actions in seven other states where voters have approved abortion rights measures, including four — California, Michigan, Ohio and Vermont — that put abortion rights in their constitution. Abortion rights measures also might appear on several other state ballots this year.

The signatures were submitted on the same day the Arizona Legislature approved a repeal of a long-dormant ban on nearly all abortions, and as a ban on most abortions after six weeks of pregnancy, before many women even know they are pregnant, went into effect in Florida.

Dakotans for Health co-founder Rick Weiland said backers of the ballot initiative gathered more than 55,000 signatures to submit to Secretary of State Monae Johnson, easily exceeding the 35,017 valid signatures needed to make the November general election. Johnson’s office has until Aug. 13 to validate the constitutional initiative. A group opposing the measure said it’s already planning a legal challenge to the petition alleging the signatures weren’t gathered correctly.

South Dakota outlaws all abortions, except to save the life of the mother, under a trigger law that took effect after the U.S. Supreme Court overturned Roe v. Wade in June 2022.

“The abortion law in South Dakota right now is the most restrictive law in the land. It’s practically identical to the 1864 abortion ban in Arizona,” said Weiland, referring to the law Arizona legislators voted to repeal Wednesday. “Women that get raped, victims of incest, women carrying nonviable or problem pregnancies have zero options.”

Weiland said the ballot measure is based on Roe v. Wade, which had established a nationwide right to abortion. It would bar the state from regulating “a pregnant woman’s abortion decision and its effectuation” in the first trimester, but allow second-trimester regulations “only in ways that are reasonably related to the physical health of the pregnant woman,” such as licensing requirements for providers and facility requirements for safety and hygiene.

The initiative would allow the state to regulate or prohibit abortion in the third trimester, “except when abortion is necessary, in the medical judgment of the woman’s physician, to preserve the life or health of the pregnant woman.”

“Our Roe framework allows for abortion in the first two trimesters,” Weiland said.

The American Civil Liberties Union of South Dakota doesn’t support the measure.

“In particular, it does not have the strongest legal standard by which a court must evaluate restrictions on abortion, and thereby runs the risk of establishing a right to abortion in name only which could impede future efforts to ensure every South Dakotan has meaningful access to abortion without medically unnecessary restrictions,” executive director Libby Skarin said in a written statement.

Planned Parenthood North Central States, the former sole abortion provider in South Dakota, hasn’t said whether the organization would support the measure. In a joint statement with the ACLU of South Dakota, the two said groups said, “We are heartened by the enthusiasm South Dakotans have shown for securing abortion rights in our state.”

Weiland said he’s hopeful once the measure is on the ballot, “another conversation will occur with some of these organizations.” He cited his group’s hard work to get the measure this far, and said measure backers are “optimistic that we’re going to have the resources we need to be able to get the message out.”

Republican opponents, meanwhile, are promising to fight the initiative. Earlier this year, the GOP-led Legislature passed a resolution formally opposing it, along with a bill for a petition signature withdrawal process. The backer of the latter bill was Republican state Rep. Jon Hansen, a co-chair of Life Defense Fund, the group promising to challenge the ballot initiative.

Hansen called the measure extreme during a forum last month.

“If the proponents of this abortion amendment wanted to just legalize rape and incest exceptions, they could have done that, but they didn’t do that,” Hansen said at the time. “Instead, what they wrote is an amendment that legalizes abortion past the point of viability, past the point where the baby could just be born outside the womb and up until the point of birth.”

Hansen also asserted that the measure would not allow “basic health and safety standards for mothers” in the first trimester.

Weiland has repeatedly disputed Hansen’s claims, and called Life Defense Fund’s planned court challenge “just a desperate charge on their part.”