Four years after she won a City Council seat, making her what is believed to be Georgia's first transgender politician, Michelle Bruce is battling a lawsuit launched by an unsuccessful opponent who claims she misled voters by running as a female.

Bruce, a tall woman with shoulder-length graying hair, said she has always identified herself as transgender. "I've always been Michelle," she said. "If someone has a problem with that, I can't help them. It's a personal issue."...