Though Maine was the fifth state to legalize same-sex marriage, it was the first where the Legislature approved the measure and it was signed by the governor without being directed by the courts. No such legislation has been approved by citizens in a statewide vote.
In addition to legalizing gay marriage, the law also reaffirms religious freedoms.
"This does not authorize any court or other state or local governmental body, entity, agency or commission to compel, prevent or interfere in any way with any religious institution's religious doctrine, policy, teaching or solemnization of marriage within that particular religious faith's tradition as guaranteed by the Maine Constitution," the law reads.
Both supporters and opponents of the law anticipated a people's veto question to appear on the fall ballot and have launched professional campaigns focused on fundraising and get-out-the-vote efforts.
None of the arguments either for or against the law plow new ground. Supporters say the issue is about fairness and equality, and opponents say it impugns upon tradition and will have a detrimental effect on society.
"I think we all want to live in a state that values and treats everyone equally under the law," said Jesse Connolly, campaign manager for the group No on 1/Protect Marriage Equality.
Marc Mutty, chair of the group Stand for Marriage Maine, said supporters of the repeal believe in equal rights for all, including gays and lesbians, but by changing the marriage law to include them, traditional marriage has been destroyed.
"The definition of marriage is so important because it has a impact on society — if marriage means this or that, it is diminished; it can't have value if it means multiple things," he said. "You are looking at a major cultural shift that a lot of people are just not aware of."
The new law offers a union between a man and woman who are capable of reproduction no "special place" in society anymore, Mutty said.
Connolly countered that the referendum is fundamentally about "Maine values."
"What kind of state do we want to all live in? I think we want to live in a state that values our friends and our neighbors, that values people that have been in committed relationships and that recognizes for too long they've been discriminated against based on this section of Maine law and that it's time to change," he said.
Much like the campaign to ban gay marriage in California last year, national groups have dumped hundreds of thousands of dollars into the efforts of both sides.
Groups such as the National Organization for Marriage, Focus on the Family, the Roman Catholic Diocese and the Knights of Columbus have contributed to the repeal effort, according to state campaign finance reports. Those contributing to uphold the law include the Human Rights Campaign, the American Civil Liberties Union, Gay and Lesbian Advocates and Defenders and the LGBT Mentoring Project.
Polls indicate Maine voters are nearly split on the issue, with few undecided, and both sides agree it will be close.
"It's a toss-up right now in terms of polling," Mutty said.
Connolly said he doesn't have a crystal ball, but "it's going to be a very close election."