PORTLAND — Maine’s highest court has denied a national group’s final appeal to shield the names of donors to its campaign in 2009 against same-sex marriage in Maine.

In a unanimous decision released Thursday, the Maine Supreme Judicial Court rejected the argument by the National Organization for Marriage that disclosing its donors’ identities to Maine’s ethics commission would infringe on its First Amendment right of freedom to associate.

While the decision ends the years-long legal battle, it likely will have little impact on when the list of donors will be made public.

The ethics commission said last month, when lawyers made oral arguments before the high court, that the list could be released within months regardless of the decision.

Maine is now one of 12 states where same-sex marriage is legal, but four years ago the state’s voters overturned a law passed by the Legislature to allow it. The National Organization for Marriage played a key role in that hard-fought and emotional referendum campaign, which ended with 53 percent of the voters rejecting gay marriage.

The organization was the largest contributor to the political action committee Stand for Marriage Maine, giving $1.9 million.

Since that campaign, the ethics commission has been investigating whether the national organization violated Maine law by failing to register and file reports about its fundraising and spending.

For more than three years, the organization fought in state and federal courts to keep the names of its donors confidential. It had lost the federal case before Thursday’s ruling.

The U.S. Supreme Court refused in October to hear its appeal of the Maine law that would require it to name its contributors. As a result, the organization was forced to release one list of donations to the ethics commission in January.

While Maine’s high court was considering NOM’s appeal, it refused to delay the release of donors who contributed $5,000 or more, a group covered by separate language in Maine’s disclosure law.

The organization’s attorney, Kaylan Phillips, confirmed last month that it had complied by giving the commission a list of donations, with the names of individual donors given as “John Does.”

The ethics commission is now using that list to determine whether the group should have registered as a political action committee. The commission may release names only after it completes its investigation.

Maine’s campaign disclosure law requires groups that spend more than $5,000 to influence the outcome of a referendum to register with the ethics commission as ballot question committees.

In its appeal to the U.S. Supreme Court, the organization claimed that the law is too vague and inhibits free speech by discouraging donations.

Jonathan Wayne, the ethics commission’s executive director, has said that the release of individual donation amounts enabled commission staff members to pick up their investigation into whether NOM violated state campaign law.

However, state officials are barred from releasing donors’ names while the investigation is ongoing, he said last month.

Wayne said by phone Thursday that he has not seen the Supreme Judicial Court’s decision and could not respond to it. But he said the investigation is continuing.

“The commission’s staff would like to finish their investigation within the next two to three months and report back to the commission after receiving additional information and responses from the National Organization for Marriage,” Wayne said.

Phillips, based in Indiana, was out of her office Thursday and did not immediately return a message seeking comment.

The National Organization for Marriage continues to fight same-sex marriage legislation in other states throughout the country.

Scott Dolan can be contacted at 791-6304 or at:

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