WASHINGTON – Three of Maine’s four members of Congress are urging the U.S. Supreme Court to strike down a law that denies federal benefits to same-sex couples, while Republican Sen. Susan Collins continues to hedge on the closely watched social issue.

“Sen. Collins will carefully follow the Supreme Court’s consideration of this important case,” her spokesman, Kevin Kelley, said Friday when asked about the pending court hearings on same-sex marriage.

Maine’s Reps. Chellie Pingree and Mike Michaud and Sen. Angus King were among 212 Democratic and independent members of Congress who joined a “friend of the court” brief in support of ending the Defense of Marriage Act.

Signed into law in 1996 by President Bill Clinton, the act defines marriage as “only a legal union between one man and one woman.”

That language means that gay and lesbian partners in Maine and other states that allow same-sex marriage are still treated differently from heterosexual married couples for Social Security and veterans’ benefits, immigration, taxes and other federal programs.

“DOMA imposes a sweeping and unjustifiable federal disability on married same-sex couples,” reads the brief, one of dozens filed before this month’s hearings on the constitutionality of the act and California’s ban on gay marriage. “It is ‘class legislation’ that lacks any rational connection to legitimate federal interests, thus violating the Fifth Amendment’s equal-protection guarantee.”

Collins, a socially moderate Republican, has earned praise from gay-rights groups for her leadership on issues that are important to the lesbian, gay, bisexual and transgendered, or LGBT, community.

But she did not offer a position Friday on the Defense of Marriage Act or the other Supreme Court case challenging the constitutionality of California’s ban on gay marriage.

In a written response, Kelley pointed out the act was signed into law before Collins’ election in November 1996. In 2004 and 2006, she voted against proposals to amend the U.S. Constitution to restrict marriage to unions between one man and one woman.

“Sen. Collins voted against these federal constitutional amendments defining marriage because she believes the issue of same-sex marriage is best addressed by the individual states, as the voters of Maine decided in November,” Kelley said. “Recognizing that LGBT Americans should be protected from discrimination, Sen. Collins has led efforts in Congress to extend federal benefits to gay men and women and their families.”

Collins will be up for re-election in 2014 and there has been persistent speculation about whether she will face a challenge from the conservative or tea party wings of the Republican Party.

Attitudes about same-sex marriage in Maine appear to be shifting steadily, as shown by November’s vote legalizing it and the lack of controversy since the weddings began at the end of last year.

Despite her reluctance to weigh in on the Supreme Court cases, Collins has not shied away from publicly supporting changes to federal laws criticized as discriminating against the LGBT community.

In 2010, she and Sen. Joseph Lieberman, I-Conn., co-sponsored the Senate bill that ended the “Don’t ask, don’t tell” policy prohibiting military service by openly gay and lesbian people.

Collins has also sponsored or supported bills to allow domestic partners of federal employees to receive federal benefits, and to prohibit job discrimination based on sexual orientation.

Collins is now the primary co-sponsor — and the only Republican co-sponsor — of a bill that would treat same-sex “permanent partners” the same as traditional couples in immigration law.

For instance, the Uniting American Families Act would allow a gay or lesbian U.S. citizen to sponsor a foreign-born spouse for a green card, just as is allowed for heterosexual married couples.

Collins’ record is encouraging to groups that hope the high court will overturn the Defense of Marriage Act.

“We are very grateful to the three members of our delegation who signed the DOMA ‘friend of the court’ brief,’” Ian Grady, spokesman for the organization Equality Maine, said Friday. “We are looking forward to having a conversation with Sen. Collins about how DOMA is hurting same-sex couples in Maine. And we are optimistic about that conversation because of her past support for LGBT issues and her support for the Uniting American Families Act.”

The case over the Defense of Marriage Act involves an elderly Connecticut woman, Edith Windsor, who had to pay more than $300,000 in federal estate taxes after the death of her partner of 40-plus years, to whom she was legally married.

The California case to be heard by the Supreme Court seeks to overturn that state’s Proposition 8, outlawing same-sex marriage.

The ruling could be broadened to apply to states with similar prohibitions.

More than 100 Republicans who have held office, held leadership positions or served in top government jobs filed a brief Friday urging the court to overturn Proposition 8.

Among them was Mark Ellis, a former chairman of the Maine Republican Party who is still involved in state politics.

Kevin Miller can be contacted at 317-6256 or at:

kmiller@mainetoday.com

On Twitter: @KevinMillerDC