A state judge in Lafayette on Monday declared Louisiana’s ban on same-sex marriage unconstitutional, a ruling that conflicts with a federal judge’s decision earlier this month upholding the state ban.

Fifteenth Judicial District Judge Edward Rubin’s decision, made in an adoption case involving two women in Lafayette, will have no immediate impact on the status of same-sex marriages in Louisiana.

Rubin’s strike at the ban is another salvo in a legal battle that soon could be settled by the U.S. Supreme Court.

“This is a major win for Louisiana families, but it’s the first step in a long road,” said Chris Otten, chairman-elect of the Forum for Equality Louisiana.

The group led the recent challenge to Louisiana’s same-sex marriage ban in federal court in New Orleans.

In that case, U.S. District Judge Martin Feldman upheld the state law in a ruling earlier this month that went against the trend of federal judges in other states striking down similar bans.

The state will appeal Rubin’s Monday ruling to the Louisiana Supreme Court and has asked the judge to put his decision on hold pending the appeal, said attorney Kyle Duncan, who has been hired by the state Attorney General’s Office to handle challenges to Louisiana’s same-sex marriage ban and who also argued the case before Feldman.

“In Louisiana, the constitution defines marriages as that which occurs between a man and a woman. The state will continue to register marriages and adoptions according to that definition,” the Attorney General’s Office said in a written statement issued through Duncan.

Rubin’s ruling came in an adoption case involving Angela Costanza and Chasity Brewer, who were legally married in California and now live in Lafayette.

The adoption court case, as well as Rubin’s ruling, are sealed from public view, but an attorney representing the women, Joshua Guillory, said Costanza sought to be legally recognized as a parent to Brewer’s son.

As part of that process, the women first asked that their out-of-state marriage be recognized as legal in Louisiana, Guillory said.

Guillory said he received an OK from the judge to discuss only the broad outlines of Monday’s ruling.

He said Rubin found Louisiana’s ban on same-sex marriage violated the due process and equal protection clauses of the 14th Amendment and the U.S. Constitution’s “full faith and credit clause,” which calls for each state to recognize the laws and court decisions of other states.

“They were legally married out of state,” Guillory said.

Duncan said he was perplexed that Rubin did not even mention Feldman’s ruling on the same issue just weeks before in federal court.

Keith Werhan, a constitutional law professor at Tulane University Law School, said he doesn’t believe a state judge in Lafayette has an obligation to follow Feldman’s decision, because Feldman serves in the New Orleans-based Eastern District of the federal court system in Louisiana and Lafayette Parish is in the Western District.

“Technically, it doesn’t have any power to bind them,” Werhan said.

Werhan also said he would expect the Louisiana Supreme Court to hold off ruling on any challenges to the same-sex ban that are based on the federal constitution, predicting the issue probably will be settled in short order by the U.S. Supreme Court.

A U.S. Supreme Court decision would trump a decision by the Louisiana Supreme Court on the issue.

“Often, a (state) court in that circumstance would say, ‘We are going to stay back. … It’s all going to be resolved by the U.S Supreme Court,’ ” Werhan said.

Duncan said he plans to push forward with his appeal of Rubin’s ruling.

“We are going to ask to move this as quickly as possible,” he said. “We can’t know how quick the U.S. Supreme Court will react.”

Supporters of same-sex marriage counted the ruling as a major win, despite the still unsettled nature of the law.

“Today is a victory for Angela, Chasity and their son, Nicholas, to be sure, but it is also a victory for thousands of citizens who work hard and contribute to this state every day, hoping that one day soon they too will be allowed the freedom to marry the person they love,” Equality Louisiana President Tim S. West said in a written statement.

“Unlike Judge Feldman’s uninformed and mean-spirited ruling earlier this month that dismissed real Louisiana families, Judge Rubin’s ruling today demonstrates that Feldman doesn’t represent Louisiana values.”