As Justice Lewis F. Powell Jr. was struggling with how to cast the decisive vote in a 1986 Supreme Court case that would end up devastating the gay rights movement, he told his fellow justices that he had never met a homosexual. In truth, one of his four law clerks that term was gay. The atmosphere at the court today is far different from 1986, with a pace of change that may have surpassed that in the rest of society. Openly gay law clerks are now common in the chambers of both liberal and conservative justices. In January, Chief Justice...