The poll was conducted by Hart Research Associates, the same group that does surveys for Gov. Martin O'Malley. The pollster used live callers to contact 504 respondents, and reported a margin of error of 4.5 percent.
Maryland's General Assembly passed legislation legalizing gay nuptuals durng this year's regular session. The law does not go into effect until Jan. 2013, and opponents have gathered enough signatures to put the measure on the November ballot.
Josh Levin, the campaign manager for Marylanders for Marriage Equality, which is defending the law, said the results show "We continue to have the momentum."
Opponents dismissed the results Thursday afternoon. “Polls don’t accurately reflect how voters feel on the marriage issue," said Mary Ellen Russell, the executive director of the Maryland Catholic Conference. "Given the increasing atmosphere of intimidation against people who believe marriage should be between a man and a woman, one of the few places left where you can openly express your true opinion is in the privacy of the voting booth.”
Hart has polled on this question several times in Maryland during the past year, though this is the first of their polls to be made public. Numbers have moved around quite a bit.
In Jan. 2011, a Hart poll showed 49 percent in favor and 41 percent against. Support for same-sex marriage dipped in Aug. 2011 to 44 percent supporting and 46 percent opposed.
But in March 2012, Hart's numbers started trending in favor of same-sex marriage, by a closer 51 percent to 43 percent. The latest numbers, showing a 14 point margin of support, "is a marked improvement" according to the poll memo.
The poll also shows that African-American voters in the state are evenly split on the issue, 44 percent supporting to 45 percent opposed. Black voter make up a sizable portion of the state's Democratic voters -- and other polls have shown them to be cool to the idea.
Hart attributes the shift to President Barack Obama's announcement earlier this year that he supports same-sex marriage, which the pollsters say "has resulted in a durable shift in attitude among African-American voters."