DES MOINES, Iowa — Supporters of the nation’s strictest abortion law are hoping a lawsuit filed against the Iowa measure will bring the issue back before the U.S. Supreme Court, but constitutional experts say that’s unlikely because of a legal maneuver by abortion-rights groups.

The Iowa affiliates of the American Civil Liberties Union and Planned Parenthood filed a lawsuit this week challenging the constitutionality of a law set to go in effect on July 1 that would prohibit most abortions in the state once a fetal heartbeat is detected. That’s around the six-week mark of pregnancy. However, the groups filed their complaint in state court in Des Moines, and it focuses on alleged violations of Iowa’s constitution rather than federal constitutional law.

The distinction is important, said Columbia Law School professor Katherine Franke. It complicates the legal avenue for challenging Roe v. Wade, the landmark 1973 U.S. Supreme Court ruling that established a woman’s right to terminate a pregnancy until a fetus is viable.

“The Iowa Supreme Court is the court of last resort on how to interpret the Iowa Constitution,” she said. “They’re raising it exclusively as a state constitutional issue for obvious reasons. They don’t want to be baited into having this case be the opportunity for the U.S. Supreme Court to revise Roe. It’s a smart strategy.”

Rita Bettis, legal director for the ACLU of Iowa, said during a news conference that the Iowa Supreme Court has previously recognized a woman’s right to an abortion when it struck down an effort by a

state medicine board to ban telemedicine abortions.

The practice continues to allow women in rural areas to get abortion pills without the need for an in-office consultation in a city clinic.

“We think that that’s a clear indication of what we already know, which is that the Iowa Constitution robustly protects exactly these fundamental individual rights that include a woman’s right to access a safe and legal abortion,” she said.

The makeup of the Iowa Supreme Court remains mostly the same. Bruce Zager, an appointee of former Republican Gov. Terry Branstad, will retire in September. New Gov. Kim Reynolds, Branstad’s former lieutenant governor, will fill the vacancy.

Justice Daryl Hecht, an appointee of former Democratic Gov. Tom Vilsack, has missed hearing some cases recently as he undergoes treatment for melanoma, a form of skin cancer. But court officials say he’ll continue to participate as treatment allows.

Iowa Republican lawmakers who passed the abortion ban this year believe the state courts strategy isn’t foolproof.

Rep. Steven Holt, a Republican from the small western Iowa city of Denison, said he believes the court case will raise enough federal questions that it will provide an avenue for questions before the U.S. Supreme Court.

“None of us have a crystal ball,” he said. “The only thing that I can say is that numerous state laws that are challenged end up before the United States Supreme Court.”

Todd Pettys, a professor at the University of Iowa College of Law, said that comes down primarily to whether the Iowa Supreme Court makes a ruling on the lawsuit that relies on federal law.

“If this case does wind up in front of the United States Supreme Court, it’s going to be because the Iowa Supreme Court decided intentionally to write an opinion that left open that possibility, and I doubt that they would do that,” he said.

Such an appeal would likely be in the form of a petition asking the U.S. Supreme Court to directly hear the case. Franke said there is a chance a group of women or other party opposing abortion could file a federal constitutional challenge to the law just to get it into federal court.

“It would be a staged challenge but I wouldn’t be surprised to see that,” she said.

The legal strategy for the state is still being sorted out.

Iowa’s longtime attorney general, Democrat Tom Miller, said in a letter after the lawsuit was announced that he would not defend the law based on a belief that the measure “would undermine rights and protections for women.”

Chuck Hurley, chief counsel for the Family Leader, a faith-based group in Iowa that opposes abortion, said there are legal motions the state could make to ask the U.S. Supreme Court to step in and review the case.

He said he has discussed such strategy with the Thomas More Society, a conservative Chicago-based law firm, which has agreed to defend the law for free.

A spokesman for the firm didn’t respond to a request for comment.

Hurley acknowledged the odds are against the high court doing so, but he said it will come down to more conservative-leaning justices getting on the bench, which he believes is possible as the lawsuit makes its way through the court system.

“That’s the biggest element by far,” he said. “Frankly, the only element.”