The Associated Press:

The Washington state Senate passed a bill Wednesday night that would legalize same-sex marriage, setting the stage for the state to become the seventh to allow gay and lesbian couples to wed.

The measure now heads to the House, which is expected to approve it and could take action on it as early as next week. Gov. Chris Gregoire supports the measure and has said she will sign it into law, though opponents have promised to challenge it at the ballot with a referendum.

The packed public galleries burst into applause as the Senate passed the measure on a 28-21 vote after nearly an hour and a half of debate. Four Republicans crossed party lines and voted with majority Democrats for the measure. Three Democrats voted against it.

... Nearly a dozen amendments were introduced, including several that passed that strengthen legal protections for religious groups and organizations. A handful were rejected, including one that would exempt photographers, cake decorators and other business owners who object to gay marriage from the law, and another that called for a referendum clause to be added to the bill.

Sen. Dan Swecker, R-Rochester, argued that the proposed law alters the definition of marriage and "will lead to the silencing of those who believe in traditional marriage."

"It's ironic how a bill which purports to be about ending discrimination leaves the door open so far for discrimination going in the other direction," he said. "I'm extremely concerned that without additional protections, this legislation will create a hostile environment for those of us who believe in traditional marriage."

Even though the referendum clause amendment was rejected, opponents have already promised to file a challenge to the legislation. But that can't be done until after it is passed by the full Legislature and signed into law by Gregoire. Opponents then must turn in 120,577 signatures by June 6.