Born and raised in Birmingham, he first came out as gay in 1998. His early teens were filled with taunting and bullying that he described as a “daily gantlet.” He ran away from home. Before his junior year, looking for a fresh start, he transferred to a different school and did not reveal his sexual identity to classmates or teachers.

Mr. Rafferty attended the University of Alabama at Birmingham and joined the Marine Corps. While in the military, he avoided conversations about personal relationships, although he was already in a relationship with the man who would later become his husband. Only after leaving the Marines, just over a decade ago, did he become more open about his sexuality.

He spent nine years as an employee of Birmingham AIDS Outreach, working with young people and organizing H.I.V. testing events across the region. He ran for the Legislature in 2018, becoming only the second openly gay lawmaker elected in the state. The first, Patricia Todd, held the same Birmingham-area House seat before him. At her retirement, Ms. Todd said that she was most proud of the Alabama legislation that she had helped to block — measures she considered harmful to L.G.B.T.Q. constituents.

Mr. Rafferty, too, has spent his term in the Legislature working to prevent new restrictions on gay and transgender young people. He testified against such proposals. He connected constituents with Republican proponents of the measures, hoping to change the lawmakers’ minds by making them more comfortable with gay and transgender people and explaining the burdens they said such legislation would create. He brought medical experts and local organizers who provide support to L.G.B.T.Q. youth to the Capitol.

When the legislation came to the floor of the House, Mr. Rafferty appealed to his colleagues on the basis of their conservatism, arguing that they had no business involving themselves in the decisions of parents, doctors and children. “Where’s the freedom in that?” he asked. “Where’s small government in that?”

His efforts were welcomed by gay and transgender residents, who saw him as a singularly important ally. “He has earned a degree of trust with trans people, not just with his representation but because he is part of our extended community,” said Sydney Duncan, a lawyer and head of L.G.B.T.Q. legal services at the organization where Mr. Rafferty once worked. “He has taken the time to educate himself on these issues, and that has earned him a pass with us to be able to represent us and talk to us and see that we are treated well.”