After failing to reach consensus last month on three other versions of a constitutional ban, the Legislature returned to take up a new compromise proposal that would ban gay marriage but allow civil unions.
Lawmakers imposed a time limit on the debate, agreeing to take a vote by 5:30 p.m. That did not sit well with some lawmakers.
"We're going to limit debate at a constitutional convention with the whole country watching us? I can't believe it," said Rep. George Peterson, a Republican who supports a gay marriage ban.
The state's highest court ruled in November that it was unconstitutional to prevent gays from marrying — a ruling that sparked a legislative scramble to amend the state constitution. The earliest the constitution could be amended is 2006. Under the court's ruling, gay marriages will begin in Massachusetts on May 17.
House Speaker Thomas Finneran, a staunch opponent of gay marriage, and Senate President Robert Travaglini, who oversees the constitutional convention, have said they believe they now have the support to pass the compromise.
They ultimately need at least 101 votes among the 200-member Legislature to pass a proposed constitutional amendment this year, and set up another vote in the 2005-06 legislative session.
Reaching any accord has been difficult, with lawmakers as divided as the general public on an issue that is inextricably linked to tradition, religion and sexuality. Lawmakers suspended their last constitutional convention Feb. 12 after two days of emotional debate ended in impasse.
Nationally, much has developed since last month's deadlock. San Francisco started issuing marriage licenses to gay couples, a legally questionable move soon followed by cities both large and small. As thousands rushed to wed, President Bush urged Congress to move swiftly to enact a federal ban on same-sex marriages.
But nowhere have lawmakers been faced with a message as strong as the one Massachusetts' highest court sent in November.
"This is the first state where the legality is clear," said Rep. David Linsky, a Democrat who supports same-sex marriage.
Whatever action lawmakers take should not bear too much weight nationally because it still must clear several legislative hurdles before reaching voters, said Arline Isaacson, co-chair of the Massachusetts Gay and Lesbian Political Caucus.
"So for at least two and a half years, gay people will be able to marry, and that's what has upset non-Massachusetts folks the most," Isaacson said.
By 6 a.m. Thursday, hundreds of people stood at the Statehouse entrance and others chanted, waved flags and sang Gospel music on the sidewalks.
"No Hatred. Just loving biblical truth," read posters held by some of the opponents of gay marriage.
Lynn Tibbets, 50, of Boston, held a sign urging "No discrimination in the constitution."
"It used to just make me mad — the people on the other side. Now it just makes me sad," Tibbets said as she choked back tears.