By John Wagner
Washington Post Staff Writer
Thursday, December 9, 2010; 1:13 AM

A majority of senators on a key committee in Maryland now favor legalizing same-sex marriage, making it increasingly likely that the state will join five others and the District in allowing such unions.

Membership changes on the panel, where same-sex marriage bills have previously died, are among a handful of shifts produced by last month's elections. Collectively, they appear to have tipped the balance on the most high-profile social issue the General Assembly will consider during its upcoming 90-day session.

Republican gains Nov. 2 in other state legislatures are expected to lead to more conservative social policies. But Democrats in Maryland bucked the trend, adding two seats to their majority in the Senate. Moreover, when the General Assembly convenes next month, a few senators who lost primaries will be replaced by Democrats more supportive of same-sex unions.

"This has truly been a transformative election on this issue," said Sen. Richard S. Madaleno Jr. (D-Montgomery), an openly gay lawmaker who has sponsored same-sex marriage legislation and plans to push for passage this session. "I could not have hoped for a better result. You can see a real path to enacting this legislation."

Despite Maryland's reputation as a liberal state, lawmakers have been slower to embrace same-sex unions than their colleagues in some other blue states, in part because of the strong opposition of the Catholic and black churches.

The legislation would remove a long-standing requirement in Maryland law that recognizes only marriages between a man and a woman.

Leaders of the House of Delegates, traditionally the more liberal chamber on social policy, said they have the votes to pass the measure. And Gov. Martin O'Malley (D) has said he would sign such a bill, although he has previously supported the alternative of civil unions.

Some potential hurdles remain - both inside and outside the State House - before Maryland can become the latest state to allow same-sex marriage since Massachusetts began doing so in 2004 and the District followed suit in March.

If a same-sex marriage bill is approved, advocates on both sides say they expect opponents to take advantage of a provision in Maryland that allows residents to petition recently passed laws to the ballot. A successful signature drive would put the measure on hold, pending the results of a statewide referendum in November 2012.

Support for ballot measures can be difficult to gauge this far out, but a Washington Post poll conducted in May found that 46 percent of Marylanders favored legalizing same-sex marriage, 44 percent opposed it and 10 percent had no opinion.

Those results reflected rapidly evolving attitudes on an issue that tends to break along generational lines. In late 2007, an identical Post poll question found 44 percent in favor overall and 51 percent opposed in Maryland.

In the nearer term, opponents in the Senate are expected to mount a filibuster to block the legislation. That would require a super-majority to move forward - including support from some more conservative Democrats opposed to the measure but willing to allow an up-or-down vote.

Senate President Thomas V. Mike Miller Jr. (D-Calvert), who opposes gay marriage, said that chances of a bill passing his chamber are significantly greater in the coming session than ever before. Miller, who has a reputation for iron-clad control of his chamber, said he would vote against the legislation but work to cut off the expected filibuster.

"I believe every important issue should be voted on by the full chamber at least once," he said.

Miller stopped short of predicting the outcome, saying that he has not focused on the issue. But several people close to him said he made the crucial new committee assignments - which were made public Friday - knowing that one result would probably be passage of a same-sex marriage bill.

Those who spoke about Miller's thinking requested anonymity because they are not authorized to speak for him.

In the Senate, legislation rarely advances to a vote by the full chamber without a positive recommendation from the committee that considers it.

In past years, no more than four or five senators on the 11-member Judicial Proceedings Committee publicly committed to voting for a same-sex marriage bill.

Of the 11 senators who will be seated next month, six have either served as co-sponsors of such bills or said recently that they would support the measure. Six votes are needed to send the bill to the full chamber.

Two factors proved crucial in the changed calculus. With their gain in the Senate, Democrats were allotted an additional seat on the committee. And Sen. C. Anthony Muse (D-Prince George's), a minister who opposes gay marriage, requested reassignment to another committee for unrelated reasons.

"We've been on the razor's edge in terms of passage the last couple of years, and these election results create a healthy, pro-marriage majority in the General Assembly," said Sen. Jamie B. Raskin (D-Montgomery), a committee member who supports same-sex unions.

Sen. David R. Brinkley (R-Frederick), the chamber's incoming minority whip, said the bill will face a Republican-led filibuster if it goes to the full chamber. The question is whether enough Democrats would try to block the bill, he said.

"It will put some of the conservative Democrats in a tough spot in terms of where they want to go with it," Brinkley said.

Short of the nuptials, Maryland has granted gay couples some of the same visitation and health-care rights that marriage affords. And in February, Maryland Attorney General Douglas F. Gansler (D) said state agencies should recognize same-sex marriages from states where they are legal.

The improved prospects for the measure in Maryland come as Republicans are pondering conservative shifts in social policy after their national gains last month.

In New Hampshire, one of the five states that allows gays to wed, conservatives are considering repealing the law after wresting control of both chambers of the legislature. And Minnesota lawmakers, who were poised to take up the same-sex marriage issue, are backing off because of GOP gains there.

In Maryland, Democrats, with their two-seat pick-up, will hold 35 of 47 seats when the General Assembly convenes next month.

Republicans gained six seats in the House. But the party remains such a distinct minority - with 43 of 141 seats - that there is unlikely to be much impact.

"I believe the votes are there for marriage equality to pass," said House Majority Leader Kumar P. Barve (D-Mongtomery).