ST. PAUL, Minn. — Last year’s emotional campaign over a proposed constitutional ban on same-sex marriage in Minnesota cost the two main competing groups a combined $18 million, according to campaign finance reports released Friday.

That made it Minnesota’s most costly election, although spending on the failed state constitutional amendment was just a slice of the millions consumed by all the races on the ballot.

Minnesotans United for All Families, the leading group on the winning side, spent about $12.4 million last year. It was far more than the $5.6 million that Minnesota for Marriage put into its effort, at least one-fifth of that from the Catholic church.

The total spending on the ballot question climbs even higher when campaign activity from 2011 and by other groups is included.

Those dollars fueled a highly visible campaign waged with television advertising, leaflets, bumper stickers, billboards and door-to-door canvassers.

Richard Carlbom, who managed the anti-amendment campaign, said his group knew at the outset it would take more than $10 million to win given that voters in other states had yet to reject a gay marriage ban.

He said the organization’s 80,000 contributors and 250,000 email addresses will pay dividends as Minnesota lawmakers now debate whether to legalize gay marriage.

Scott Dibble, an openly gay lawmaker in Minnesota, said last month he will take the lead in the state Senate on a bill to legalize same-sex marriage during the 2013 legislative session.

Tags: Marriage Equality, Minnesota

Filed under: Minnesota