Supporters of LGBT rights are gearing up for yet another fight at the ballot against a proposed constitutional amendment that would ban same-sex marriage.

This time around, the theater for battle is Minnesota.

Donald McFarland, spokesperson for the new coalition known as Minnesotans United for All Families, said nearly 1,000 people have already signed up to work against the amendment on the campaign website within 48 hours of passage by the legislature.

“They are signing up by the hundreds to help us,” McFarland said. “It’s incredible actually. The outpouring of support to what happened Saturday night is as great as I have ever seen in my political career — and I’ve been doing this for 30 years.”

On Saturday, the Minnesota State House gave final approval to the proposed constitutional amendment by a vote of 70-62. The State Senate had already passed the measure.

The Republican-controlled legislature’s approval sends the measure to the state electorate. If a majority of voters approves the marriage ban in 2012, it will become part of the state constitution.

Same-sex marriage is already prohibited in Minnesota by statute, but passage of the amendment would prohibit the legislature from legalizing same-sex marriage in the future or the state courts from finding a right to same-sex marriage in the state constitution.

A coalition of LGBT organizations — including national groups such as the Human Rights Campaign, the National Gay & Lesbian Task Force and Freedom to Marry as well as local groups OutFront Minnesota and Project 515— launched a new coalition, Minnesotans United for All Families, immediately upon approval of the amendment.

The plans for the nascent campaign are still being developed. An official campaign manager has yet to be named. Still, the campaign has already piqued the interest of supporters of same-sex marriage.

McFarland said the biggest goal at this point is to start a conversation with the Minnesota electorate about the love and commitment of same-sex couples and reminding voters that discrimination runs contrary to state values.

“The biggest component of the next many, many months is the fact that we’ll have an army of people, an army of volunteers, an army of smart, smart Minnesotans who want to help,” McFarland said. “That’s an advantage that we have ten-fold over the other side.”

McFarland, the de facto head of Minnesotans United for All Families until a campaign manager is selected, said he’s been involved in Minnesota politics for nearly 10 years.

In 2006, he was state director of American Voters, an organization that works to advance liberal-leaning policies and expand access to the ballot. Last year he worked as a communicators officer for the Minnesota Democratic Party.

McFarland’s LGBT portfolio includes working as the gay liaison in Philadelphia for Bill Clinton’s 1992 presidential campaign and serving as a board member for Project 515.

Money is already a concern for the new coalition. Proponents of the anti-gay amendment in Minnesota have pledged to raise $4.7 million to ensure its passage. McFarland said he wants to raise the amount dollar-for-dollar to thwart the effort.

“Things like fundraising goals are still being really fleshed out, but I will tell you that I am committed to raising $4.7 million to match what the other side claims it will spend,” McFarland said.

The output for the campaign is still under deliberation, but McFarland said he envisions paid television advertisements as well as additional paid media presence.

As supporters of same-sex marriage gear up for the fight, anti-gay groups, such as the Minnesota Family Council, are working for passage of the amendment.

The Minnesota Family Council had urged passage of the amendment, asserting that gays and lesbians eat human excrement, that gays and lesbians are more likely to be pedophiles and engage in bestiality, and that domestic partner benefits are a recruiting tool. The anti-gay group has since the scrubbed the language from its online promotions.

McFarland said maintaining a “respectful” tone throughout the campaign is a priority and criticized the anti-gay group’s tactics in the debate.

“It’s just vile language,” McFarland said. “It has no place here. It certainly has no place in Minnesota.”

The Minnesota Family Council didn’t respond to the Washington Blade’s requests for comment for this article.

Polling on the amendment in Minnesota is limited, but is promising for those working to defeat the measure. A poll published May 13 by the Minnesota Star Tribune found that 55 percent of respondents oppose adding such language banning same-sex marriage to the state constitution while 39 percent favor such a measure.

McFarland said he thinks the polling is “absolutely” comforting news, but shouldn’t be seen as a guarantee that Minnesota voters will reject the proposed constitutional amendment.

“A year-and-a-half is a long time, so who knows?” McFarland said. “We want to beat this ballot question and we’re going to do everything we can to do that.”

Issac Wood, a political scientist at the University of Virginia, said the 2012 presidential election — and the strength of President Obama — may have an impact on the result of the Minnesota ballot initiative.

“Often pundits and the media talk about referendums driving voter turnout and influencing elections, but in this case we may see the reverse,” Wood said. “If Obama is able to win a sizable victory in Minnesota again in 2012, which he won by 10 percentage points in 2008, perhaps he could draw enough socially liberal voters to the polls to defeat the marriage amendment as well.”

Wood said based on the history of the marriage ballot initiatives, Minnesota voters may approve the amendment. Still, he observed that national opinion on marriage has been evolving rapidly in the past year.

“Public opinion on the issue seems to be turning recently, with new polls showing nationwide approval of gay marriage on the rise,” Wood said. “Whether that approval has risen quickly enough to stem the tide of marriage amendments remains to be seen.”

Although there are promising poll numbers, a victory at the polls on the marriage issue is an extremely rare feat for LGBT rights supporters. Each time that a ban on same-sex marriage has come to voters at the state level, it has almost always been approved.

In 2006, Arizona voters rejected an amendment that would have made a ban on same-sex marriage and marriage-like unions part of the state constitution. However, voters passed a similar amendment in 2008 that banned only same-sex marriage.

Despite the dismal batting average, McFarland said he plans to draw on lessons from those earlier battles and has had conversations with those who’ve gone before him.

“We’re currently talking to others in other states that have gone before us in these battles over same-sex couples’ ability to get married,” McFarland said. “We very much intend to be mindful of all of them as we move forward.”

Prominent Minnesotans have already spoken out against the amendment. On Wednesday, Gov. Mark Dayton (D) penned  a symbolic veto. Since the measure is a constitutional amendment, he doesn’t have the authority as governor to stop the initiative from becoming part of state law.

“Although I do not have the power to prevent this divisive and destructive constitutional amendment from appearing on the Minnesota ballot in November 2012, the legislature sent it to me in the form of a bill,” Dayton said. “Thus, symbolic as it may be, I am exercising my legal responsibility to either sign it or veto it. Without question, I am vetoing it.”

McFarland said he appreciates Dayton’s vocal opposition to the amendment — and said the governor was speaking out against it even before the legislature gave final approval — but he said he doesn’t think Dayton will play a large role in the campaign against the initiative.

“He’s the governor and his job is to be governor, not to be part of the campaign,” McFarland said. “His campaign was last year. Will he speak out about this issue? I believe he will because he feels passionately about this, like so many other Minnesotans.”

Another prominent politician from Minnesota has voiced a similar objection. On Monday, U.S. Sen. Al Franken (D-Minn.) also slammed the amendment in a statement to media outlets.

“Every Minnesotan deserves dignity and equal treatment under the law, and our state’s same-sex couples should have the same right to marry as anyone else — period,” Franken said. “This amendment would do nothing more than write discrimination into our state’s constitution and add to the barriers same-sex couples already face to the full recognition of their families. I’m hopeful that common sense and compassion will prevail and that this amendment will be defeated.”

Also earlier this week, White House spokesperson Shin Inouye issued a statement to the Washington Blade on President Obama’s position on the measure.

“The President has long opposed divisive and discriminatory efforts to deny rights and benefits to same sex couples or to take such rights away,” Inouye said. “While he believes this is an issue best addressed by the states, he also believes that committed gay couples should have the same rights and responsibilities afforded to any married couple in this country.”

The statement doesn’t explicitly mention the proposed constitutional amendment in Minnesota. Additionally, the statement reaffirms Obama’s lack of support for same-sex marriage rights by saying the issue is “best addressed by the states.”

McFarland said he’s “thrilled” the White House issued a statement, but dodged on whether he’d like to see more from Obama over the course of the campaign against the amendment.

“I really have no answer to that,” McFarland said. “I’m not going to make a call in the press to the White House. I’m not comfortable with that.”