Maryland Gay Marriage Ballot Initiative
Question 6 on the Maryland ballot was a referendum petition that passed Tuesday, allowing gay and lesbian couples to obtain a civil marriage license. REUTERS

Gay marriage supporters are slated to score significant victories in states across America via four ballot initiatives.

The biggest wins for marriage equality advocates were the projected approvals of measures in Maryland, Maine and Washington state that would make them the first states in the nation to institute same-sex marriage via referendum.

A fourth ballot initiative in Minnesota put the question of whether to define marriage as between a man and a woman in the state constitution. It seemed likely to fail, which would deal another significant blow to foes of marriage equality.

As voters across the country reacted emotionally to President Barack Obama's re-election on Tuesday, the focus of many election watchers concerned with social issues shifted to ballot initiatives, including those concerning gay marriage. Setting the stage to reverse a 2009 initiative that banned gay marriage, Maine voters were projected a little after midnight Eastern time on Tuesday to legalize the practice in the state, with the initiative's supporters holding a lead of 52 to 48 percent with 37 percent of ballots counted, according to the Christian Post.

The Associated Press predicted late Tuesday that the vote would result in a win for the initiative, making Maine the first state that the AP had ever declared would pass such a measure.

The Maryland initiative to legalize gay marriage in the state -- dubbed Question 6 -- was projected to win at about 11:30 p.m., at which time supporters had a thin lead with about 51.5 percent of the vote with 84 percent of precincts reporting, according to the Associated Press. CNN predicted shortly after midnight Wednesday that Maryland would pass the initiative.

Referendum 74 in Washington, which would legalize same-sex marriage in the Northwest state, was projected to win at about 11:30 p.m. ET Tuesday, when The Seattle Times reported that early vote counts showed the initiative winning 53 percent to 47 percent.

And in Minnesota, the ballot referendum to define marriage as between a man and a woman was behind by a 49 to 47 percent margin shortly after midnight Tuesday, according to the Christian Post.