But several plot twists — an ambitious Democratic governor as the main character, a multimillion-dollar outreach effort and the involvement of key Republicans — led New York to a different final scene than in Maryland.
The Marylanders, whose own efforts fell short during the 2011 legislative session, say they are planning to adopt some of New Yorkers' tactics when they try again next year.
"New York proves this can happen," said Del. Keiffer Mitchell, a Baltimore Democrat who championed the Maryland bill in the House of Delegates. "I was watching that pass and dreaming, because it should have been us."
Opponents, meanwhile, predicted New York would have no impact on the debate here.
"Everybody across the country was shocked that Maryland did not legalize same-sex marriage," said Del. Don H. Dwyer Jr., one of the legislation's most vocal opponents.
"But our Republicans stood strong and are going to stay strong, whereas in New York, they didn't have the guts to stand up and do what's right," the Anne Arundel County Republican said.
"Plus," Dwyer added, "Democrats remain afraid of retribution at the polls if they vote for same-sex marriage. That's not going to change."
On the top of the advocates' to-do list: Get the governor out front.
Both New York and Maryland are led by Democrats with national political ambitions.
New York Gov. Andrew M. Cuomo, who campaigned last year on legalizing same-sex marriage, made it a key priority to get a bill to his desk in the first year of his term.
Maryland Gov. Martin O'Malley, who is in the first year of his second term, said he would sign such a bill if it were approved by the General Assembly, but he did not push the issue publicly.
Democratic state Sen. Richard S. Madaleno Jr. of Montgomery County, the Senate's only openly gay member, said he has asked O'Malley to sponsor a gay marriage bill next year in every conversation they've had during the past four months.
"I think people from around the state and the country are going to come to Martin O'Malley and say, 'You should be doing what Andrew Cuomo did because it's the right thing to do and it's smart politics,'" Madaleno said.
Patrick Wojahn, chairman of the board of directors of Equality Maryland, the state's leading lobbying group for gay rights, said the governor "could make it more of a priority."
"While Governor O'Malley has certainly been an ally, and we certainly appreciate his work, it's clear that Governor Cuomo really went to bat for this issue and made it a top priority," Wojahn said. "I know he stands with us. He is on our side, but I think that he could make it more of a priority."
O'Malley said his decision to work behind the scenes, rather than pushing the bill as Cuomo did, was strategic.
"If I thought [making gay marriage part of his administration's legislative agenda] would have helped rather than hurt its chance of passage, I'd have done it," O'Malley said Monday.