Opponents plan a day of prayer that a same-sex marriage bill will fail, a slew of Sunday sermons focused on traditional marriage and a rally in Annapolis. They've united forces under a new banner, the Maryland Marriage Alliance.
Last spring a measure that sought to legalize same-sex marriage in Maryland cleared the state Senate but stalled in the House of Delegates. Leaders pulled the bill from the House floor when they realized they didn't have the 71 votes needed for passage.
Since then, there have been some changes in the political landscape. New York joined five other states and Washington, D.C., in legalizing same-sex marriage, garnering national attention for Gov. Andrew Cuomo.
Days before the first same-sex marriage couples married in New York, Gov. Martin O'Malley, who is thought to be testing the waters for a 2016 presidential race, completed his own 180-degree turn and said he would put the full resources of his office behind passing such a measure here.
"Marriage equality will be part of the legislative package, and I am hopeful and optimistic that the men and women of the General Assembly will pass a bill," O'Malley, a Democrat, said last week.
The most recent poll suggests that state voters are evenly split on the issue, with Democrats more likely to support same-sex marriage than Republicans.
It is the last chance for lawmakers to pass the legislation with the knowledge that, if petitioned to referendum, the question would be on the 2012 ballot. Some have flatly stated they don't want the controversial measure going to the voters in 2014, when state senators and delegates will be up for re-election.
Since the Maryland Senate is on record supporting the bill, the fight is expected to be in the House of Delegates.
"We'll find out when we come back to session whether some legislators feel comfortable acknowledging that civil marriage is a civil rights issue," said House Speaker Michael E. Busch.
By his count, up to 10 delegates in the 141-member House are still on the fence about the issue. With the chamber so closely divided, they are expected to determine the outcome.
One person in that category is Del. John Olszewski, a Baltimore County Democrat who expressed concerns about the legislation last session but has left the door open to voting yes.
He said his main concern is how the law would impact churches, mosques and synagogues whose members abhor same-sex marriages. "We have to be crystal clear on the religious exemptions," Olszewski said in a recent interview.
Olszewski is looking for protections beyond simply letting religious institutions bar the ceremonies. He said the law could, for instance, make clear that religious organizations would not have to rent a house to a same-sex couple.
"If Maryland is going to move forward, it is very important that appropriate religious safeguards are included," he said.
Both sides are coy about the delegates on their target list, but say they are well positioned to make their case.
The new support coalition, Marylanders for Marriage Equality, includes groups that were not actively pushing the bill last session, including the Maryland chapter of the American Civil Liberties Union, the Baltimore NAACP, and the Service Employees International Union.
Kevin Nix, a spokesman for the coalition, said the addition of labor and civil rights groups allows the movement to "touch" more lawmakers. "Each coalition partner brings certain expertise and skills and relationships to the table," Nix said. "Having more of that is only helpful."