The US Supreme Court said on Tuesday that Colorado's ban on so-called "conversion therapy" was unconstitutional, violating the First Amendment of freedom of speech.

Colorado's law currently bans licensed mental healthcare providers from seeking to change the sexual orientation or gender identity of LGBTQ patients under 18 through therapy. Violators face fines of up to $5,000 (€4,339).

Over 20 US states and much of Europe, including Germany, have banned "conversion therapy." Both the American Psychiatric Association and the American Psychological Association have opposed the practice.

The UN has also called for a global ban on the practice, arguing that they are discriminatory, humiliating and a violation of individuals' bodily integrity.

Colorado's ban was challenged legally by Kaley Chiles, a Christian licensed counselor who argued that the law violated the constitution's provision of freedom of speech.

Eight of the Supreme Court justices backed Chiles's challenge, just one opposed, thus reversing a lower court's decision that had previously upheld the law.

Colorado's Democratic Governor Jared Polis, the first openly gay man to be elected as governor, signed ‌the ban into law in 2019.

Republican President Donald Trump's administration had supported Chiles' challenge. 

'Censorious governmenment'

Conservative ‌Justice Neil Gorsuch led the majority opinion against the law.

"Colorado's law addressing conversion therapy does not just ban physical interventions. In cases like this, it censors speech based on viewpoint," Gorsuch wrote.

"Colorado may regard its policy as essential to public health and safety. Certainly, censorious governments throughout history have believed the same. But the First Amendment stands as a shield against any effort to enforce orthodoxy in thought or speech in this country," he added.

Justices sent the case back to the lower court for further examination under a more rigorous First Amendment standard. The ruling still leaves the door open for a ban on non-speech forms of conversion therapy, including so-called "aversive" physical interventions.

Chiles' lawyer, James Campbell, of the conservative Alliance Defending Freedom, celebrated the ruling, calling it "a significant win for free speech, common sense,and families desperate to help their children."

Two liberals join majority opinion

Recently, many Supreme Court decisions have fallen along ideological lines, with a 6-justice majority of conservatives to three liberals.

But on Tuesday, two liberal Justices, Elena Kagan and Sonia Sotomayor, also rejected the ban.

"Once again, because the State has suppressed one side of a debate, while aiding the other, the constitutional issue is straightforward," Kagan wrote.

Justice Ketanji Brown Jackson was the only dissenter. In her opinion, she accussed her colleagues of opening "a dangerous can of worms" by undermining states' ability to regulate a medical practice that "risks grave harm to Americans' health and wellbeing."

"The Constitution does not pose a barrier to reasonable regulation of harmful medical treatments just because substandard care comes via speech instead of scalpel," she wrote.

Edited by: Alex Berry