ST. PAUL — A historic vote Thursday in the Minnesota House positioned the state to become the 12th in the country to allow gay marriages and the first in the Midwest to pass such a law.
Lawmakers approved it 75 to 59, a critical step for the measure that would allow same-sex weddings beginning this summer. Six months ago, voters turned back an effort to ban gay marriage in the Minnesota Constitution.
The state Senate plans to consider the bill Monday and leaders expect it to pass there, too. Governor Mark Dayton has pledged to sign it into law.
‘‘It’s not time to uncork the champagne yet. But it’s chilling,’’ Representative Steve Simon, a suburban Democrat who backed the bill, said at a rally in the state Capitol rotunda minutes after the vote.
Representative Karen Clark, sponsor of the bill, said her only goal was equal treatment under state law for same-sex couples. In a deeply personal speech, the Minneapolis Democrat talked of the support she got from her own family after coming out as gay decades ago.
‘‘My family knew firsthand that same-sex couples pay our taxes, we vote, we serve in the military, we take care of our kids and our elders, and we run businesses in Minnesota,’’ she said.
Four of the House’s 61 Republicans voted for the bill, while two of its 73 Democrats voted no. None of the four Republicans committed support beforehand; one, Representative Jenifer Loon, said she made up her mind during the three-hour House debate.
‘‘There comes a time when you just have to set politics aside and decide in your gut what is the right thing to do,’’ said Loon, whose suburban district southwest of Minneapolis voted strongly against last fall’s gay marriage ban. The other Republicans to vote for gay marriage also hail from suburban or exurban districts: Pat Garofalo of Farmington, David FitzSimmons of Albertville, and Andrea Kieffer of Woodbury.
The two Democrats who voted no, Patti Fritz of Faribault and Mary Sawatzky of Willmar, represent largely rural districts where the gay marriage ban was backed by a majority of voters. But most of the Democrats from rural, more socially conservative areas ended up voting for the bill.
Opponents argued that it would alter a centuries-old conception of marriage and leave those people opposed for religious reasons tarred as bigots.
‘‘We’re not. We’re not,’’ said Representative Kelby Woodard, a Republican from Belle Plaine. ‘‘These are people with deeply held beliefs, including myself.’’
House Republican leader Kurt Daudt acknowledged that views on gay marriage are changing, but said the bill’s sponsors stood to alienate thousands of Minnesotans who still believe in the male-female definition of marriage.