The bill was given preliminary approval by the state Senate by a 25-22 vote, with a final vote on the measure scheduled for Thursday morning.
Opponents of the bill tried to attach several amendments to it Wednesday, and many failed, including one that would have barred any mention of same-sex marriage in public elementary schools.
Republican Bryan Simonaire lamented issues he said occurred in Massachusetts elementary schools after same-sex marriage was approved there. It brought a response from Democrat Jamie Raskin.
"The school did not have to notify parents that they were going to be teaching same-sex marriage. As a matter of fact, they said they couldn't even remove them from the class. That's where we're heading...so that's my concern. That's not where we're heading. If you look at the regulation, this will not be taught until high school," Raskin says.
Senate President Mike Miller brought an end to what was expected to be a long day of debate, calling some of the amendments "out of line."
"It was far from what the original concept of the bill was -- which I voted against, which is to permit gay marriages in the state of Maryland," Miller says.
If the Senate OKs the bill, it is expected to pass the House, and Gov. Martin O'Malley has said he will sign it.