The United States Supreme Court appears poised to side with a challenge against a Colorado law that bans psychotherapists from conducting “conversion therapy” on minors in an attempt to influence their gender identification or sexuality.

On Tuesday, the high court, which has a six-to-three conservative majority, heard arguments in the case, which weighs whether the ban violates the protections for free speech under the First Amendment of the US Constitution.

The complaint was brought by licensed counsellor Kaley Chiles, a Christian who claims Colorado’s law infringes on her free speech rights.

But the state has defended its law. Colorado Solicitor General Shannon Stevenson argued that the ban regulates harmful conduct, not speech.

The 2019 Colorado law prohibits licensed mental healthcare providers from seeking to change a minor’s sexual orientation or gender identity with a predetermined outcome in mind. That practice, known as conversion therapy, has been often associated with religious prohibitions against gay or transgender identities.

Detractors have warned that such “therapy” is pseudoscience and can be harmful, not to mention discriminatory, for LGBTQ youth.

Justices weigh arguments

Colorado maintains that Chiles’s allegations of free-speech violations are hypothetical because the state has not actually disciplined her.

But the Alliance Defending Freedom, a conservative organisation representing Chiles, has argued that the danger is that professionals might censor themselves for fear of punishment.

James Campbell, a lawyer for Chiles, told the justices that Colorado’s law “forbids counsellors like Kaley Chiles from helping minors pursue state-disfavoured goals on issues of gender and sexuality”.

Conservative Justice Samuel Alito seemed to embrace that claim that Colorado’s law marginalises certain points of view.

At one point in Tuesday’s hearing, Alito told Stevenson that her state’s measure allows therapists to help a patient feel comfortable about being gay but bars them from helping a patient who seeks to “end or lessen” their same-sex attraction.

“It seems to me your statute dictates opposite results in those two situations,” Alito said, adding, “Looks like blatant viewpoint discrimination.”

Conservative Chief Justice John Roberts also pushed back on Colorado’s law and on Stevenson’s assertion that it only regulates the conduct of licensed therapists.

The court’s precedents make clear that “just because they’re engaged in conduct doesn’t mean that their words aren’t protected”, Roberts said.

Concerns from medical professionals

Colorado is one of more than 20 states in the US that have banned conversion therapy, a widely discredited practice in the medical field.

The American Academy of Child and Adolescent Psychiatry is one of the groups that has spoken out against the practice.

On its website, the academy warns that conversion therapy could trigger or worsen mental health conditions among minors. It also says the practice could stigmatise LGBTQ identity.

“These interventions are provided under the false premise that homosexuality and gender diverse identities are pathological,” it explains. “They are not; the absence of pathology means there is no need for conversion or any other like intervention.”

In 2019, the Williams Institute, a think tank at the School of Law at the University of California at Los Angeles, issued a report that found as many as 698,000 LGBTQ adults had undergone conversion therapy at some point in their lives. That included about 350,000 who received treatment as adolescents.

“This court has recognised that state power is at its apex when it regulates to ensure safety in the healthcare professions,” Stevenson told the justices in her opening remarks.

“Colorado’s law lies at the bull’s-eye centre of this protection because it prohibits licensed professionals from performing one specific treatment because that treatment does not work and carries great risk of harm.”

The Supreme Court’s ruling is expected by the end of June.

In recent rulings, the court’s conservative majority has largely sided with arguments that expand the concept of religious freedom, even in cases that raise questions of anti-LGBTQ discrimination.

At the end of its 2024-2025 term in June, for instance, the majority rendered a decision that allowed parents to opt out of school materials that include LGBTQ themes.