OLYMPIA — The last time same-sex marriage was debated in the state Capitol, the Legislature’s sole gay lawmaker watched as his colleagues passed the state’s version of the Defense of Marriage Act in 1998 banning gay marriage. Fourteen years after that “lonely moment,” Sen. Ed Murray stood in the wings as lawmakers approved his bill allowing gay and lesbian couples to marry.

“I didn’t think I would be in office to see marriage equality passed,” Murray, D-Seattle, said Wednesday night. “It was incredibly moving to watch a new generation of gay and lesbian lawmakers in the House standing up and carrying the torch.”

The Washington House passed the bill on a 55-43 vote earlier in the day. Supporters in the public-viewing galleries cheered as many on the Democratic side of the House floor hugged.

The state Senate approved the measure last week. Wednesday’s vote sends the bill to Democratic Gov. Chris Gregoire, who is expected to sign it into law next week. She issued a statement saying it was “a major step toward completing a long and important journey to end discrimination based on sexual orientation.”

The passage came a day after a federal appeals court declared California’s ban on gay marriage unconstitutional, ruling it was a violation of the civil rights of gay and lesbian couples.

Democratic Rep. Jamie Pedersen, a gay lawmaker from Seattle who also has sponsored gay rights bills for several years, cited Tuesday’s ruling by the San Francisco-based 9th U.S. Circuit Court of Appeals during his remarks on the House floor. He noted a section that stated “marriage is the name that society gives to the relationship that matters most between two adults.”

Several Republicans argued that the bill goes against the tradition of marriage. Rep. Jay Rodne, R-Snoqualmie, said the measure “severs the cultural, historical and legal underpinnings of the institution of marriage.”

Several Republican amendments were rejected, including one that would have added private businesses and individuals, such as bakers and photographers, to an exemption in the measure that doesn’t require religious organizations or churches to perform marriages and doesn’t subject them to penalties if they don’t marry gay or lesbian couples. Another would have required a one-month residency requirement before people could get married in Washington state.

Two Republicans — Reps. Glenn Anderson of Fall City and Maureen Walsh of College Place — crossed the aisle and voted in favor of the bill. Three Democrats voted against it: Reps. Chris Hurst of Enumclaw, Steve Kirby of Tacoma and Mark Miloscia of Federal Way. Democrats hold a 56-42 majority in the House.

The proposal would take effect 90 days after the session ends next month, but opponents have promised to fight back with a ballot measure that would allow voters to overturn the legislative approval.

If opponents gather enough signatures to take their fight to the ballot box, the law would be put on hold pending the outcome of a November election. They must turn in more than 120,000 signatures by June 6 if they want to challenge the proposed law. Otherwise gay couples could wed starting in June.

Washington state has had domestic partnership laws since 2007, and more than a dozen other states have provisions, ranging from domestic partnerships to gay marriage, supporting same-sex couples.

Gay marriage is legal in New York, Connecticut, Iowa, Massachusetts, New Hampshire, Vermont and Washington, D.C. Lawmakers in New Jersey are expected to vote on gay marriage next week, and Maine could see a gay marriage proposal on the November ballot.

Proposed amendments to ban gay marriage will be on the ballots in North Carolina in May and in Minnesota in November.

California’s voter-approved same-sex marriage ban, known as Proposition 8, was rejected by a three-judge panel of the 9th Circuit on Tuesday. The panel gave gay-marriage opponents time to appeal before allowing same-sex weddings to resume. The judges also said the decision only applies to California, even though the court has jurisdiction in nine western states.

Washington state’s momentum for same-sex marriage has been building and the debate has changed significantly since 1998, when lawmakers passed Washington’s ban on gay marriage. The constitutionality of that law ultimately was upheld by the state Supreme Court in 2006. But earlier that year, a gay civil rights measure passed after nearly 30 years of failure, signaling a change in the Legislature.

The quick progression of domestic partnership laws in the state came soon after, with a domestic partnership law in 2007. An “everything but marriage” expansion was later upheld by voters years later.

In October, a University of Washington poll found that an increasing number of people in the state support same-sex marriage. About 43 percent of respondents said they support gay marriage, up from 30 percent in the same poll five years earlier. Another 22 percent said they support giving identical rights to gay couples, without calling the unions “marriage.”

If a challenge to gay marriage law was on the ballot, 55 percent said they would vote to uphold the law. And 38 percent said they would vote to reject a gay marriage law.

Same-sex marriage also has the backing of several prominent Pacific Northwest businesses, including Microsoft, Nike and Starbucks.

In Seattle’s Capitol Hill neighborhood on Wednesday, 27-year-old Nicolle Edwards said that the possibility of a referendum to the soon-to-be new law was a concern, but that she was happy her lawmakers approved gay marriage.

“Any step in the direction of equal rights is something to celebrate,” said Edwards, who is gay.