As you walk down a particular hallway on the seventh floor of the Humphrey Building in Washington, D.C., you'll find a line of photographic portraits of all the people from years past who have led the Public Health Corps at the federal Department of Health and Human Services. Only one of those portraits is of a transgender person: Adm. Rachel Levine, who served for four years as President Biden's assistant secretary for health. She was the first transgender person to win Senate confirmation, and her portrait has been displayed in the hallway since soon after she was confirmed in 2021....