OLYMPIA, Wash. - The state Supreme Court upheld a ban on gay marriage Wednesday, saying lawmakers have the power to restrict marriage to unions between a man and woman.

The 5-4 decision disappointed hopeful gay-marriage advocates and leaves Massachusetts as the only state to grant full marriage rights to gay and lesbian couples. It was the latest in a series of significant court rulings favoring gay-marriage opponents.

The court’s majority overruled two lower courts that had found the state’s 1998 Defense of Marriage Act, which limits marriage to opposite-sex couples, violated the state constitution and its Equal Rights Amendment.

However, three majority justices invited the state Legislature to take another look at the gay marriage ban’s affect on same-sex couples.

“Given the clear hardship faced by same-sex couples evidenced in this lawsuit, the Legislature may want to re-examine the impact of the marriage laws on all citizens of this state,” wrote Justice Barbara Madsen, with Justice Charles Johnson and Chief Justice Gerry Alexander concurring.

The two other justices in the majority, James Johnson and Richard Sanders, agreed with the outcome but more actively opposed gay marriage.

“The Legislature was justified in enacting DOMA to clarify and reaffirm Washington marriage law by a compelling governmental interest in preserving the institution of marriage, as well as the healthy families and children it promotes,” Johnson wrote. “This conclusion may not be changed by mere passage of time or currents of public favor and surely not changed by courts.

The 38 plaintiffs in the case were dismayed at the ruling, but said there would be momentum to push for gay marriage rights in the Legislature.

“We will not give up,” said Lisa Stone, lawyer for the plaintiffs.  “All it means is that we’re taking a deep breath, we’re putting our shoulders back, and we’re settling into our role as advocates, as attorneys, as activists and as citizens of our state to ask the Legislature and the fair minded people of Washington to help us achieve marriage equality.”

“I believe that our constitution should treat all of its citizens the same, and in this case the court was willing to treat my family differently than other families,” said Brenda Bauer of Seattle, who sued along with her longtime partner Celia Castle. “Today’s a pretty sad day for our family.”

"I just feel very deep sadness," said Pastor Dave Shull, one of the plaintiffs in the case, along with his partner Pastor Peter Ilgenfritze. "It's largely because this was an opportunity for the court to say that all people indeed are equal under the law and there should not be any artificially constructed walls to separate people or deny them their basic rights."

Democratic leaders in the state House and Senate did not commit to any course of action early Wednesday.

“Just as the public is divided over the issue, so is the Legislature,” said Senate Majority Leader Lisa Brown, D-Spokane.The four-justice minority harshly criticized the ruling.

Justice Mary Fairhurst said the majority of bowing to public opinion by upholding the law.

“Unfortunately, the (majority) are willing to turn a blind eye to DOMA’s discrimination because a popular majority still favors that discrimination,” Fairhurst wrote.

Nineteen gay and lesbian couples seeking to marry had challenged the constitutionality of Washington’s 1998 Defense of Marriage Act, which limits marriage to heterosexual couples.

Judges in King and Thurston counties overturned it in 2004, citing the state constitution’s “privileges and immunities” section.

The state appealed, arguing that it has a legitimate interest in regulating relationships that produce children.

Gay marriage opponents were surprised, but grateful.

“This is more than we could have imagined. We are shocked, and pleasantly shocked. We were prepared for the other direction,” said Jon Russell, field director for the conservative Faith and Freedom Network, which intervened in the case.

“In America there’s an institution called marriage.  It’s unique and it unites a male and a female, a husband and a wife, for the benefit of procreation, parenting and caring for children,” said Jeff Kemp, Families Northwest president.

King County Executive Ron Sims, who helped foster one of the original lawsuits by same-sex couples seeking to marry in liberal Seattle, said his next step would be to push for civil unions.

“There’s still hope in the long run,” Sims said. “I still dream for a just society.”

Forty-five states have laws banning gay marriage or limiting marriage to between a man and a woman.

In other recent rulings on the issue, courts reinstated voter-approved bans on gay marriage in Nebraska and Georgia, and Tennessee’s Supreme Court ruled that voters there should have a say on allowing gay marriage.

Massachusetts’ high court—the same court that issued the historic ruling that has allowed more than 8,000 same-sex couples since 2004 to marry in that state—ruled a proposed state constitutional amendment to ban gay marriage could go on the ballot if approved by the Legislature.

In Connecticut, a judge found gay and lesbian couples had not been harmed by that state’s decision to grant them civil unions but not marriage. Vermont also allows civil unions that confer the same legal rights as heterosexual married couples.

Congress recently rebuffed a move to get a constitutional amendment banning same-sex marriage.

KING 5's Chris Daniels contributed to this report.