The effort to legalize gay marriage in Maryland is effectively dead for this year.

After nearly three hours of passionate debate, the Maryland House decided on Friday to return the bill to committee, effectively killing the effort.

Democratic leaders conceded they moved to shelve the legislation after concluding Thursday night that the measure wouldn't survive a House vote.

“I fully expect to see a bill come in front of the Maryland House of Delegates next year,” Democratic House Speaker Michael E. Busch told reporters on Friday. “This is a distance run, not a sprint. … We never asked anyone to support this bill unless they felt comfortable with it.”

Supporters fought off four amendments on Wednesday and another two on Friday.

The House's seven openly gay delegates implored colleagues to vote for the bill.

“It's love that makes a family, but it's marriage that protects it,” Delegate Heather R. Mizeur, who is legally married to Deborah Mizeur, told lawmakers. “Do the right thing: cast your vote in favor of love.”

Delegate Luke H. Clippinger pleaded: “Today I ask you for your vote to make me a whole citizen of this state.”

Supporters blamed the loss on the House's November 2 shift to the right.

Delegate Anne R. Kaiser, a Democrat from Montgomery, told the Washington Post that the chamber had lost five or six pro-gay marriage Democrats last year.

Brian Brown, president of the National Organization for Marriage (NOM), the nation's most vociferous opponent of gay marriage, cheered the news on Twitter: “Hero of the day, Maryland Delegate Emmett Burns called n word for opposing gay marriage. Stands tall.”

After Maryland decided to recognize the out-of-state marriages of gay couples last year, Burns called the opinion “a bucket of warm spit.”