A coalition of reproductive-rights advocates is suing the state of Idaho over a new law banning interstate travel related to abortion, arguing the law violates constitutional protections for free speech and travel.

The advocates, based in Washington and Idaho, believe that Idaho’s decision in April to become the first state to ban interstate travel for reproductive care sets a precedent for policing travel that other abortion-hostile states are likely to follow.

“Once you do this, do you get to say anytime anyone leaves your state for something that you disagree with, it becomes illegal?” said Wendy Heipt, senior reproductive health and justice counsel at Seattle’s Legal Voice, which has filed a preliminary injunction to stop the law from going into effect, arguing: “Suppose they change their mind when they get there. How do you stop them?”

The law, signed April 5 by Idaho Gov. Brad Little, makes it a felony to assist a minor seeking an abortion, with violations punished by three to five years of prison time. The language of the law, however, doesn’t answer Heipt’s questions. That’s one of three claims made in the suit, brought on behalf of three plaintiffs: the Northwest Abortion Access Fund, whose service area includes Idaho and Washington; the Indigenous Idaho Alliance, which serves Indigenous communities across the Northwest; and an individual, Lourdes Matsumoto, a Boise-based attorney who often works with victims of sexual violence who may need abortion care, including minors.

The advocates say the new law could be interpreted broadly and potentially used to arrest and prosecute someone who helps a minor access an abortion even if they had obtained parental consent before assisting the young person.

According to the complaint, Washington Gov. Jay Inslee requested that Gov. Little veto the ban. In response, Little doubled down on a previous statement he’d made, arguing that the law doesn’t prohibit interstate travel, but keeps young people from traveling to other states for abortion without parental consent. Last August, Little signed off on Idaho’s near-total abortion ban, a development that has led pregnancy care providers to leave the state.

For the plaintiff organizations, which connect young people with abortion resources as part of their work, knowing where this policy’s legal line is could mean the difference between operating within the law and going to jail.

The 14th Amendment’s due-process guarantee requires that citizens be informed of what conduct is illegal. The lawsuit argues that the Idaho law is too ambiguous to meet this standard, citing confusion among the policy’s own drafters about “even what constitutes a violation.” This confusion was expressed by bill sponsor Idaho State Sen. Bill Lakey, who, according to the lawsuit, said in a Senate State Affairs Committee hearing that “recruiting, harboring and transporting, those are descriptive words, I guess the court would have to decide if the conduct constitutes one of those three things.”

The lawsuit also argues that the law violates protections for freedom of travel, a fundamental right, and freedom of speech, since it places limits on sharing information about abortion with young people.

“If you read the law, it says you can’t recruit or harbor or transport, and I have no idea what recruit means” in this context, said Heipt. “Does recruit mean I can’t tell a minor about her options? Does recruit mean I can’t suggest that she make a phone call? We’re not really sure where that goes, but it clearly impacts speech and what we can tell someone with the information we can impart. And even if you don’t like what I’m saying, you can’t stop me from saying something legal just because you don’t like it.”

Although it was the first to pass an abortion travel ban, Idaho wasn’t the first state to attempt to criminalize travel related to abortion. Since the U.S. Supreme Court overturned Roe v. Wade last year, other states have tried to crack down on one of the only options available to people seeking abortions in states where the medical service is no longer legal. Those measures have largely failed.

Idaho’s success can be traced to its target: Historically, curtailing abortion access for young people has been a more successful political strategy than targeting adults. Even before Roe v. Wade was overturned, many states had parental consent laws requiring a guardian’s sign-off before a minor could access abortion. (Washington isn’t one of them.) In situations where this wasn’t possible, young people had to plead their case before a judge, who would decide if they met a standard of maturity to obtain an abortion.

Idaho’s law builds on this foundation, and by calling its subject “abortion trafficking” also employs the language of sex trafficking, inviting a conflation between assisting minors in seeking abortions and coercing them into sex work.

Heipt said that characterization was disingenuous. “It is not trafficking,” she said. “It actually does a disservice to true survivors of trafficking.” In reality, she said, the law is essentially a travel ban. “They’re using very inflammatory language to create a problem that they then pretend to solve,” she said. “That problem isn’t there and if it was, this would not be the solution.”

So far no one has been prosecuted under the law, and Legal Voice is seeking an injunction to keep it from going into effect while their suit is heard.

But the law is likely to be replicated elsewhere since it employs policy ideas introduced to National Right to Life advocates last summer and outlined in a letter proposing strategies to interfere with abortion access should abortion bans not gain traction with prosecutors.

“As a result, to effectively enforce pro-life laws, a wide variety of enforcement measures will need to be adopted to supplement criminal enforcement, including licensing penalties, civil remedies, and criminal enforcement by state officials,” wrote attorneys from the Bopp Law Firm, the office led by Republican activist James Bopp, in the letter to the National Right to Life Committee sent last June. The proposed model legislation — the origin of most anti-abortion policy historically — includes a ban on “illegal abortion trafficking of a minor.”

Washington state has a new Shield Law protecting individuals from out-of-state prosecutions related to abortion, but Heipt said she was concerned Idaho’s law could still have an impact given the high interstate traffic and existing relationships among Northwest states.

“I think because our borders are so close and porous, and we have family, if you drive your niece from Idaho back to your house in Washington, you could be liable,” she said. “We don’t know how they’re going to prosecute it or where it ends. And … just as an American, one of the fundamental underpinnings of our democracy for several hundred years has been the right to travel and be treated equally from state to state.”