The Supreme Court was more than an hour into its feisty debate over gender-affirming care when Justice Ketanji Brown Jackson invoked one of the most significant civil rights precedents in the nation’s history.

The wide-ranging argument at the Supreme Court touched on the approaches of other nations, the relevance of a previous ruling protecting transgender workers from workplace discrimination and the rights of parents.

The conservative-majority Supreme Court appeared likely to uphold Tennessee’s ban on transgender-affirming health care for minors as it heard the most high-profile case of its term on Wednesday.