First there were lawsuits against Maine Gov. Janet Mills over her COVID-19 restrictions on crowd sizes and interstate travel. In three separate cases, federal judges quickly rejected the challenges and sided with the governor.

Now the state is facing a lawsuit because its vaccine mandate for health care workers does not include a religious exemption. But legal experts said it is less clear what will happen in this case because the U.S. Supreme Court has recently signaled a shift that is more sympathetic to religious liberty arguments.

“This could be one of the first challenges to raise the question of whether a COVID vaccination mandate has to have a (religious) exemption,” said Lindsay Wiley, a professor and director of the Health Law and Policy Program at the American University Washington College of Law. “It has less to do with COVID and more to do with what has changed on the Supreme Court in 2020, with the replacement of Ruth Bader Ginsberg with Amy Coney Barrett.”

The governor’s order will apply to more than 150,000 workers at hospitals, clinics, group and nursing homes, dental offices, EMS agencies and other licensed health care facilities, according to state estimates. They are required to receive their final dose of the vaccine by Sept. 17.

U.S. District Judge Jon Levy on Thursday denied a request to block the mandate at a very early stage in the lawsuit, but the plaintiffs are still asking him to issue a preliminary injunction that would prevent the state from enforcing the mandate. The court scheduled a conference in the case for Tuesday.

Vaccine mandates have long been allowed under the law. In 1905, the Supreme Court upheld a Massachusetts law that allowed cities to require people to get smallpox vaccinations and fine those who did not. Mills added the COVID-19 vaccine to those already required for health care workers, including shots against chicken pox and the common flu. The state only allows medical exemptions to those inoculations, not religious or philosophical ones.

For years, experts said, the consensus has been that religious exemptions to vaccine mandates are allowed but not constitutionally required. That precedent came from a 1990 ruling that upheld Oregon’s ban on peyote, even in Native American religious rituals. The Supreme Court said then that the state’s general ban did not violate the U.S. Constitution because it did not specifically target religion, and that concept has carried through the years since.

In April, however, the Supreme Court blocked a California rule that restricted at-home gatherings during the pandemic, which had curtailed Bible study and prayer meetings. If the state makes exceptions to the rule for secular activities, the court said, it also has to make exceptions for religious ones. Then, in June, the court said Philadelphia could not refuse to use Catholic Social Services as a foster care provider after the group refused to accept same-sex couples as foster parents. The justices kept their opinion narrow, but three conservatives said they wanted to go further and overturn that 1990 precedent.

Dmitry Bam, vice dean and professor at the University of Maine School of Law, said those rulings raised questions about the law and are likely to prompt more litigation.

“The court has been very protective of religious rights and freedoms, has been expanding the free exercise clause,” he said.

Other states, including California and New York, are also requiring some or all health care workers to get inoculated against COVID-19. But policies and exemptions vary, and the nation’s highest courts have not directly weighed in on them yet. Earlier this month, Barrett denied an effort to block Indiana University’s vaccine requirement, although students there can raise medical or religious objections. In Maine, the lawsuit is still in its first stages in the federal court in Bangor.

Wiley said the Supreme Court’s recent rulings could mean that states need to allow exemptions for religious reasons if they require them for medical ones, but the rulings haven’t been clear enough to predict for sure.

“We just don’t know,” Wiley said. “But this case could be a case that gives us a signal one way or the other.”

The complaint was filed on behalf of nine unnamed individuals, and they are represented by Liberty Counsel, a conservative group based in Florida. Their attorneys wrote that their objections are rooted in scripture and in the broad principal of rejecting any medicine or procedure developed with or aided by the use of fetal tissue.

Experts said the substance of a religious objection doesn’t matter so much as the sincerity of the belief. Dorit Reiss, a professor at the University of California Hastings College of the Law in San Francisco, said that can make it difficult to distinguish whether the objection is based in faith or in a lie. She suggested that a detailed letter or even an interview could help identify those people who are trying to abuse the process because they have other objections to a vaccine.

“It’s hard to police intentionally,” Reiss said. “The courts are worried about the states becoming the conscience police.”

One Augusta lawyer said he is working with people who have religious and medical objections to a COVID-19 vaccine mandate. Attorney Steve Smith represented a group of business owners who challenged the governor’s restrictions on their operations last year. A federal judge granted the state’s motion to dismiss that case, and the plaintiffs filed and then withdrew an appeal to the 1st Circuit Court in Boston. Smith said he has lately been hearing from professionals – including teachers, doctors and nurses – and students who do not want to get the vaccine.

“We are actively looking for plaintiffs with good facts who are against undergoing forced medical procedures,” Smith wrote in an email. “Unfortunately, as we are a private firm we are only in a position to take on paying clients who are fully aware of the professional and financial risks of taking on the ‘establishment’ position.”

Mills faced two other lawsuits that challenged her executive orders on COVID-19 restrictions.

The owners of two campgrounds and two restaurants sued Mills over a 14-day quarantine for most out-of-state visitors, which is no longer in place. A federal judge denied a motion for a preliminary injunction, and the 1st Circuit later affirmed that decision. The plaintiffs then dismissed the case.

And an Orrington church filed a lawsuit to challenge a ban at the time on gatherings of more than 10 people. A judge similarly denied a motion for a preliminary injunction, and the appeals court again supported that ruling. Then the judge granted a motion to dismiss the case entirely, and an appeal is still pending at the 1st Circuit.