The ruling leaves Massachusetts as the only U.S. state to allow same-sex couples to wed.
In a 5-4 decision, the Washington state court said lawmakers have the power to restrict marriage to a man and a woman, and it left intact the state’s 1998 Defense of Marriage Act.
Earlier in July, New York’s high court dealt homosexual couples a similar blow when it upheld a state law against same-sex marriage.
Tony Perkins, president of the Washington, D.C.-based Family Research Council, said in a statement: “We praise the Washington Supreme Court for demonstrating judicial restraint and leaving this matter where it belongs — in the hands of the people and their elected representatives. …
“Recent rulings in favor of marriage have shown that the courts are not immune to the political reality that Americans are determined to protect marriage.”