When Marcia Hams and Susan Shepherd cut into their wedding cake at city hall in Cambridge, Mass., on May 17, 2004, after becoming the first same-sex couple in the U.S. to complete a state-sanctioned marriage application, they probably hoped their union would open the floodgates for gay couples across the country. But instead, it became a high-water mark for same-sex marriage as the acrimonious debate over the issue raged on–a moment equaled only by a California Supreme Court’s ruling in mid-May overturning the state’s ban on gay marriage. Same-sex marriage has a short but heated history in the U.S. It first came to national attention in a 1993 Hawaii case, in which judges found that the state’s constitution required a compelling reason not to extend to gays equal marriage rights. The ruling prompted Congress to push through the 1996 Defense of Marriage Act, which prevented homosexual couples from receiving benefits traditionally conferred by marriage. Since then, states have scrambled to define their own stance on the issue, in some cases recognizing civil unions or domestic partnerships. Gay-marriage supporters have notched some victories, most notably in 2003, when the Massachusetts Supreme Court ruled that gays had equal marriage rights. But opponents are winning the legislative fight. Twenty-seven states have passed constitutional bans on gay marriage, while just 10 have granted rights to homosexual couples. Polls have shown that a majority of Americans–including Californians–remain opposed to gay marriage. And in response to the 2003 Massachusetts victory, 13 states passed anti-gay-marriage initiatives in the subsequent election. Gay-rights activists must hope the three states likely facing similar measures won’t follow suit this November.