Last month, the Iowa Supreme Court threw out a state law banning gay marriages, while the Vermont legislature overrode a gubernatorial veto to allow same-sex marriage there. The Washington, D.C., city council voted to recognize gay marriages from other states--setting the stage for a confrontation over the issue in Congress, which oversees District matters.

All this activity over the course of five days lent hope to gay marriage proponents in other states. "There clearly is sort of a sea change in public opinion," says Greg Harris, sponsor of a gay marriage bill in the Illinois House.

After the Massachusetts Supreme Court affirmed gay marriage rights in 2004, the issue became a centerpiece of that year's presidential campaign--but not in the way gay rights advocates would have preferred. Voters in 11 states approved constitutional bans by an average margin of 2-to-1. Some 29 states now have enacted constitutional amendments banning same-sex marriage, with California's Proposition 8 the most prominent addition last fall.

Polls indicate that most people still oppose gay marriage, but public opinion has shifted dramatically in recent years on other gay rights issues. Solid majorities now support adoption by gay couples, as well as inheritance and hospital visitation rights. There is relatively little opposition to gay clergy and teachers--or gays serving openly in the military. Support for civil unions, which was an outlying position a decade ago, has become a politically safe fallback position for gay marriage opponents, including Utah's Republican governor.