A Times examination shows how a landmark case about gender-affirming care for minors was built on flawed politics and uncertain science.

The Supreme Court's decision affects bans in about half the states, many of which have enacted other restrictions on the lives of transgender people.

In United States v. Skrmetti, the Supreme Court ruled that Tennessee’s ban on gender-affirming care for minors was not unconstitutional—the first case of its kind on which the…