By Lisa BaumannThe Associated Press

HELENA – A decision by the 9th U.S. Circuit Court of Appeals to strike down Idaho’s ban on gay marriage likely means Montana’s voter-approved ban also will be declared unconstitutional, according to an official with the Montana ACLU.

Montana’s ban is nearly identical to Idaho’s, and Montana’s federal appeals also are heard by the 9th Circuit, Montana ACLU Legal Director Jim Taylor said.

“They really went through every argument Idaho made and destroyed it,” Taylor said. “It’s clear that this is a law that’s going to apply in this (Montana’s) case.”

The ACLU and four gay couples challenged Montana’s ban in May. The lawsuit filed in federal court in Great Falls alleges the state’s constitutional ban denies same-sex couples the freedom and dignity afforded to other Montanans, and robs them of the legal protections and benefits that come with marriage.

A U.S. District Court judge still will need to rule in that case before same-sex marriage could become legal in Montana.

Taylor said in light of the 9th Circuit decision, he plans to ask the judge in the Montana case for a summary judgment, or to make a ruling without going to trial.

Republican Attorney General Tim Fox and the state can oppose the move, but Taylor said it’s unlikely to help their case.

“I’m not sure what their strategy will be, but it’s clear that the law is against them now,” Taylor said.

Fox is reviewing the 9th Circuit decision, spokesman John Barnes said.

Montana voters in 2004 approved a state constitutional amendment providing that marriage is only between one man and one woman. Fox said previously he would fight to uphold the ban.

“Until a federal court rules otherwise in a case to which Montana is a party, the definition of marriage in Montana’s constitution remains lawful and valid,” he said.

On Monday, the U.S. Supreme Court declined to hear any of the cases pending before it challenging state bans on marriage for same-sex couples.