Nearly a week after Minnesota became the 12th state to legalize same-sex marriage, opponents are strategizing what can be done to challenge the new law before wedding bells ring Aug 1.

Their answer so far seems unanimous: Not much.

"If a state decides that they want to approve same-sex marriage, we would disagree with that decision and think they will probably end up regretting it," said John Eidsmoe, senior counsel and resident scholar for the Montgomery, Ala.-based Foundation for Moral Law. "But I don't see that we have a constitutional or legal basis for saying they don't have the right to do that."

Chances for a legitimate legal challenge to Minnesota's legislation are slim if it was enacted properly, and by all accounts, it was, said Alison Gash, an assistant professor of political science at the University of Oregon who is writing a book on same-sex marriage. There appear to have been no procedural hitches in the state's 75-59 House vote and 37-30 Senate vote.

"From a legal perspective, there's nothing obvious to me, but from a democratic ballot-box perspective, there's always an opportunity," Gash said. "It's a matter of what the populace feels."

Challenges to similar legislation after the fact aren't unheard of. After the New York state legislature legalized same-sex marriage in 2011, the organization New Yorkers for Constitutional Freedoms sued for an injunction alleging that the state violated open meetings laws in deliberations before the final vote. An appeals court rejected that argument in 2012.

Maine passed a law allowing same-sex marriage three years ago, but it was successfully stalled by opponents, who wanted the issue put to voters. It was rejected at the polls, but again made the ballot in 2012, and it was approved last November.

California is the only state to have granted gay marriage via judicial ruling, then have it withdrawn after voters in 2008 passed Proposition 8, an amendment to the state Constitution that limits marriages to a man and a woman. The question of Proposition 8's validity is now before the U.S. Supreme Court. Same-sex marriage advocates challenged the amendment's constitutionality and the court heard arguments this session, along with a challenge to the Defense of Marriage Act, which prohibits the federal government from recognizing same-sex marriages. The court will rule in June.

Austin Nimocks, senior counsel for the Alliance Defending Freedom, which has testified against gay marriage in a number of states, including Minnesota, said conservative organizations like his may take additional steps to safeguard religious freedom. Although Minnesota's law provides protections for clergy opposed to same-sex marriage, Nimocks said there were "none we would consider to be constitutionally adequate."

But there's still no constitutional basis for overturning the legislation itself, said Tom Berg, professor of law and public policy at the University of St. Thomas. Objectors may make religious liberty claims when it comes to serving same-sex couples, but it can't stop the law.

"There's no religious liberty rights to not have gay marriage recognized," he said. "There may be religious liberty rights to not to facilitate a marriage in particular situations, but that doesn't go to the existence of same-sex marriage."

Fight moves to the ballot box

In the meantime, conservative action groups across the nation are now turning their focus to regaining a Republican majority in Minnesota and elsewhere during the next election cycle.

That's the plan for the National Organization for Marriage. The nonprofit, which works in opposition of same-sex marriage, intends to maintain its presence in Minnesota and has said it will spend $500,000 to defeat any Republican who voted to legalize same-sex marriage. One Republican senator and four Republican House members broke ranks to support the bill.

The group's national political director, Frank Schubert, noted that the people of Minnesota didn't vote for gay marriage — the Legislature did. He added that last November's defeat of the proposed constitutional amendment banning same-sex marriage was not an endorsement of gay marriage, rather a desire to preserve the status quo.

"There are going to be profound consequences in the political process," he said. "There's very little question that Republicans who abandon marriage will soon find themselves in a career out of politics, and I assume it will cost the DFL the majority of the Legislature."

Minnesotans United for All Families, the political group key to successfully passing the legislation, has similarly vowed to back the re-election efforts of candidates who backed the bill.

In the meantime, Eidsmoe is focusing on the upcoming U.S. Supreme Court decision, hoping that the Defense of Marriage Act is ruled constitutional. His organization believes in states' rights, even if he believes Minnesota made a fundamentally wrong choice on gay marriage.

"If it's going to be done, it should be done at the state level," he said. "We don't see anything in the U.S. Constitution that prevents states from defining marriage."

Abby Simons • 612-673-4921