Sen. Barbara Mikulski (photo courtesy wikimedia)

The senior U.S. senator from Maryland has agreed to co-sponsor legislation that would repeal the Defense of Marriage Act after LGBT rights supporters sent a petition of nearly 3,000 names to her office urging her to support the bill.

Sen. Barbara Mikulski (D-Md.) announced via her Facebook page on Thursday that she would become a co-sponsor of the Respect for Marriage Act, which is sponsored by Sen. Dianne Feinstein (D-Calif.).

The status update for her Facebook page reads: “Will co-sponsor bill 2 repeal #DOMA — All Americans entitled 2 equal protection under law & 2 be treated w/dignity & respect. #ItGetsBetter.”

In a statement provided to the Washington Blade via e-mail, Mikulski confirmed she’s a co-sponsor of the legislation.

“I am proud to co-sponsor legislation to repeal key provisions of the Defense of Marriage Act,” Mikulski said. “I believe all Americans are entitled to equal protection under the law and all of our citizens deserve to be treated with dignity and respect.”

She continued, “The Respect for Marriage Act, S.598, will allow couples who have a legal marriage in a state to have the same federal protections as every other married couple. This includes the right to receive spousal benefits under Social Security; to file joint federal tax returns and to take leave under the Family and Medical Leave Act when a spouse falls seriously ill.”

Mikulski’s support brings the total number of co-sponsors for the Respect for Marriage Act to 30. In July, the Senate Judiciary Committee held a hearing on the repeal legislation and how DOMA, which prohibits federal recognition of same-sex marriage, burdens gay couples.

Last month, a coalition of LGBT rights groups — Freedom to Marry, the Courage Campaign and Equality Maryland — delivered a petition with names from nearly 3,000 Maryland residents to Mikulski’s office calling on her to support DOMA repeal.

Rick Jacobs, chair of the Courage Campaign, said the petition drive organized by the groups helped encourage Mikulski to sign on in support.

“We battled wind, rain and fleeing residents on I-95 during a deadly hurricane named Irene just so we could deliver these signatures to Sen. Mikulski’s Baltimore office,” Jacobs said. “And it paid off. We need to keep going and continue working tirelessly until we get to the magic number of 60 votes.”

Evan Wolfson, president of Freedom to Marry, commended Mikuski for what he said was “heeding the call of families across the state.”

“Overturning DOMA’s unfair exclusion from federal protections would make a big difference in the lives of the nearly 17,000 same-sex couples in Maryland who are working hard to take care of each other and their families each and every day while being denied the critical safety-net that only marriage brings,” Wolfson said. “We look forward to working with Sen. Mikulski to grow the numbers of supporters in the Senate so that we can bring an end to marriage discrimination as soon as possible in these tough economic times”

Sen. Benjamin Cardin, the Democratic junior senator from Maryland, was already a co-sponsor of DOMA repeal, and Gov. Martin O’Malley said he’d make the legalization of same-sex marriage part of his legislative package for 2012.

Advocates had said Mikulski’s previous lack of co-sponsorship of the bill was striking because other elected officials in her state have voiced support for same-sex marriage and plans are in motion to legalize marriage rights for gay couples in Maryland next year.

Lisa Polyak, acting board chair for Equality Maryland, said her organization is “tremendously grateful” to Mikulski for joining on as a co-sponsor of the Respect for Marriage Act.

“Even more so, we’re tremendously proud that in Maryland, every statewide official — both at the state and federal level — now supports marriage equality for same-sex couples,” Polyak said. “I think they understand that it’s good public policy to treat all families equally and we look forward to the day when the federal law finally reflects that to be true.”

All Democrats on the Senate Judiciary Committee are co-sponsors of the Respect for Marriage Act, so the legislation could be reported out of committee as soon as Chairman Patrick Leahy (D-Vt.) holds a markup on the measure.

NOTE: This article has been updated.