Rejoining the gay-marriage fray, Governor Mitt Romney yesterday urged Attorney General Thomas F. Reilly to clear the way for a 2008 ballot initiative on banning same-sex marriage, arguing in a letter that ''to silence the voice of the people on a question of such great consequence would be a profound injustice."
''No matter how one feels about same-sex marriage, we should all agree that the Commonwealth's citizens should not be excluded from a decision as fundamental to society as the legal definition of marriage," Romney wrote.
Romney's letter seeks to refute legal arguments by gay-marriage supporters that Reilly should not certify the proposed initiative because it violates a section of the state constitution governing citizen-generated ballot questions. Reilly must certify the initiative before its backers can attempt to collect the 66,000 signatures needed to put it on the ballot.
On a separate track, state lawmakers are expected to consider a proposed 2006 ballot initiative on Sept. 14 that would ban gay marriage but allow civil unions. Because that proposal originated in the Legislature, which granted preliminary approval to it last year, it is governed by different rules.
Romney predicted yesterday that the Legislature's amendment would be defeated next month, because gay-marriage supporters and opponents of civil unions are now against it. Therefore, he argued, the citizen-generated initiative aimed at 2008 represents the public's only opportunity to exercise its will.
''The sole realistic opportunity for citizens to decide the definition of marriage is being decided by Reilly first," Romney said. ''If he closes off this ballot initiative, he will be saying that Reilly knows best. And in my view, the citizens know best."
Reilly, who must act on the 2008 initiative by Sept. 7, is in a thorny political situation: His competitor for the Democratic gubernatorial nomination, Deval L. Patrick, is an outspoken supporter of gay marriage, while the attorney general's own record on the issue is more complicated. Reilly, who had opposed same-sex marriage, said earlier this year that he accepts the Supreme Judicial Court's November 2003 decision legalizing gay marriage.
Reilly spokesman Corey Welford said yesterday that, ''at the end of the day, we'll do what we always do: make decisions based on the law."
Some gay-marriage supporters say it is Romney who is playing politics. Arline Isaacson, who cochairs the Massachusetts Gay and Lesbian Political Caucus, said the governor's letter is designed to impress conservative voters in other parts of the country as he prepares for a possible presidential bid.
''This is a dog and pony show for the radical right," Isaacson said. ''We believe the legal argument on our side against certification is strong, compelling, and irrefutable. Romney is being political. He is asking Reilly to make a political decision, too, but that's not Reilly's style."
Supporters of the 2008 initiative said they crafted it carefully to pass constitutional muster. For example, although they would prefer that existing gay marriages be annulled, the proposal avoids doing that in order to skirt possible constitutional problems. That means it would keep intact the roughly 6,500 gay marriages that have already taken place and those that take place before 2008.
''We went through a yearlong process of reviewing the legal landscape as well as the political landscape on this amendment," said Kristian Mineau, president of the Massachusetts Family Institute. ''That's why we crafted the wording the way that it is, so that it does not violate the Massachusetts Constitution or the US Constitution."
Gay-marriage supporters say Reilly should decline to certify the initiative because it would reverse a judicial ruling, and because it is nearly the same as a ballot measure certified in 2002 but blocked by the Legislature. The state constitution prohibits citizen-initiated ballot questions in those two situations.
In his letter, Romney argues that the proposed initiative would not reverse a judicial decision because the same-sex couples who married after the SJC decision would not be affected.
But Gary Buseck, the legal director at Gay & Lesbian Advocates & Defenders, said the governor's interpretation is overly narrow. Buseck added that Romney's argument that the people should decide whether to allow gay marriage is beside the point.
''It's not enough to say that it should be certified because it's a matter of importance," he said.
Raphael Lewis and Scott Helman of the Globe staff contributed to this report.