Instead of approving or rejecting the legislation, as expected, the House moved it backward - returning it to the committee that nearly killed it last week. House Speaker Michael E. Busch said the chamber won't entertain it again during the 2011 session, which concludes next month.
Advocates had believed that this year presented the best opportunity yet for gay marriage. While the effort ended in defeat, they could claim progress: Legislation that had never before been voted out of committee made it all the way through the Senate and onto the House floor.
Leaders say they "fully expect" the House of Delegates to take it up again next year.
"We took another step down a very long road, and we're going to continue to fight," said Del. Luke Clippinger. The Baltimore Democrat is one of eight openly gay Maryland lawmakers - one of whom came out to colleagues on the House floor Friday.
The legislation would have repealed state law defining marriage as the union of a man and a woman. It would have allowed the state to begin issuing marriage licenses to gay couples, but would not have required religious groups to perform same-sex ceremonies.
Gov. Martin O'Malley, who had said he would sign the bill but only recently began personally urging lawmakers to pass it, expressed disappointment Friday.
"I would have hoped we could have resolved this issue," he said.
Thousands of Marylanders deluged lawmakers with phone calls, e-mails and visits as gay marriage was debated, an outpouring veteran lawmakers said they had never seen.
Dozens of citizens on both sides of the issue piled into the State House on Friday to watch delegates make impassioned speeches before sending the legislation back to the House Judiciary Committee.
Advocates described the outcome as "heartbreaking," while opponents saw it as a sign that supporters overestimated Marylanders' comfort level with gay marriage.
"I'm reeling," said Ruth Siegel, a Silver Spring woman in a 12-year relationship with a woman. "This is a losing battle for them because you can't continue to oppress people forever."
Pastor Joel Peebles of Jericho City of Praise in Landover watched the debate from the gallery.
"Our objective was not to be against any group of people," he said, calling the House decision "a major benefit to our children and their children."
Had a vote been taken, House leaders said, the legislation would have come within a delegate or two of passage. Advocates believe they were a single vote shy.
"The vote would have been very close on the floor, make no mistake about it," said Busch, who supports same-sex marriage.
By moving the bill back into committee rather than taking a final vote, the 141 delegates avoided putting their positions on the record.
The decision angered observers on both sides, who said they wanted to see where each lawmaker stood.
"Not exactly profiles in courage," said Brown, of the National Organization for Marriage. The organization had pledged $1 million to defeat Republicans who supported the legislation and help re-elect Democrats who opposed it.
Busch said about 10 delegates did not feel ready to cast a vote Friday and wanted more time to learn what the bill would do. He spoke of passing legislation as "a distance run, not a sprint."
Advocates had worked furiously Thursday night to secure support from a handful of delegates who had not disclosed their voting plans, even entertaining a late attempt at further shielding religious groups that do not condone gay marriage.
Del. John A. Olszewski Jr., who had pushed for additional safeguards, said Friday evening that he believes the House can find a way to "extend marriage rights to all, but with meaningful religious protections."
An amendment that he said would do that was rejected Friday on a voice vote, as was an attempt to convert the bill into a civil-unions plan.
The Baltimore County Democrat said he would continue talking with his constituents and sorting through the issue. If he'd been asked to vote Friday on gay marriage, he said, he probably would have voted against it.
During the final hours of debate Friday, several openly gay lawmakers made personal appeals to their colleagues, while some religious lawmakers said they could turn away from their deeply held beliefs.
House Republicans, who took a position as a caucus against the bill, stayed mostly in their seats Friday as socially conservative Democrats delivered most of the opposition remarks.
Del. Don H. Dwyer Jr., the Anne Arundel County Republican who has called himself "the face of the opposition" to gay marriage, said the decision was "strategic."
"You can win a battle without ever saying a word," Dwyer said.
Del. Steve Schuh said many of the lawmakers who had planned to vote no - like himself - are not against gay people but do not want to expand the state's definition of marriage.
The Anne Arundel Republican said marriage is subsidized by the state to ensure procreation.
Del. Emmett C. Burns Jr. delivered the day's longest speech, blasting same-sex marriage supporters for calling the issue one of civil rights.
"Those who want to ride on our coattails are historically incorrect," said Burns, an African-American Democrat from Baltimore County. He said gay people had not endured the struggles of blacks, had not had crosses burned on their lawns or been thrown in a police wagon.
The House fell silent as Del. Heather Mizeur, who is Catholic and openly gay, told her story. The Montgomery County Democrat described herself as an old soul who knew at a young age that she was gay and also deeply spiritual. She said she also knew she wanted to be an elected official. She concluded by telling her colleagues she loved them.
At one point, Del. Peter F. Murphy rose to add himself to the list of openly gay delegates. The Charles County Democrat said later that he has never hidden his sexuality, but spoke to his colleagues "to make sure there was no misunderstanding."
"When you put a face on an issue and people share their stories," he said, "I can't imagine there weren't people on the floor who didn't come away with the perspective of how important it is to treat everyone equally. In that way, what happened today was not a total loss."
Audience members, too, had their own debates.
Ethan Taylor, who is raising a 3-year-old daughter with his partner, shot a baleful look at Elizabeth Wetzel, a Mormon wearing a sticker displaying a stick-figure family of a man, woman and child, while they watched the House action in the gallery.
After it ended, Wetzel approached him and said, "I wanted you to know this has been a struggle for me."
Taylor spoke of his child. When she cries, he told Wetzel, "I have to get up at night, just like a straight family does."
Wetzel was sobbing. She told Taylor that she has a gay brother.
"A lot of the language that gets out there is hateful language," she said. "It's very hard. If my religion said tomorrow that anybody can get married, I'd embrace it in a minute."
The legislation began the session with a smooth sail through the Senate, which held just a few hours of floor debate before voting 25-21 to approve the bill.
The momentum did not continue in the lower chamber.
Some of the 59 co-sponsors of the House bill backed away from it. What appeared to be an easy win in the House Judiciary Committee faltered when two co-sponsors walked out on a vote, delaying action for three days.
The legislation nearly died in committee last week, when Del. Tiffany Alston voted against it. The Prince George's County Democrat said she believes personally in the right of gay couples to marry, but based her vote on the opposition of her constituents.
House leaders leaned on committee Chairman Joseph F. Vallario Jr., who opposes gay marriage, to vote the bill to the House floor.
The next sign of trouble for the legislation came Wednesday, when a move to hand the decision directly to the voters came within nine votes of passing.
Advocates fought off other attempts to amend the bill, but could not marshal the votes for passage.
Busch said it came down to a "gut decision" to kill the bill by recommitting it to committee. He said he saved lawmakers from having to register a vote on the bill out of "fairness" because so many seemed to want more time to study the issue.
Delegates left the chamber quickly Friday, with supporters particularly unhappy.
"No one is very satisfied right now," said Del. Curt Anderson, a co-sponsor of the legislation.
Still, the Baltimore Democrat added, "What you see reflected here is exactly how it is in the state: deeply split."
Baltimore Sun reporters Yeganeh June Torbati, Annie Linskey and Timothy B. Wheeler contributed to this article.