Same-sex couples have been getting married in Minnesota for a year now and much of the controversy seems to have died down. For some supporters, however, there may still be a political price to pay.

In Eden Prairie, a high-ranking Minnesota House Republican faces a fierce Aug. 12 primary challenge in large part because of her vote to legalize same-sex marriage.

Deputy Minority Leader Jenifer Loon was one of five Republicans in the Legislature to vote for a bill last year legalizing same-sex marriage and that's made her the target of a Republican challenger, Sheila Kihne.

Kihne says she won't push to repeal the same-sex marriage law if elected and that it isn't the only reason she's challenging Loon, a three-term Republican re-elected in 2012 with nearly 60 percent of the vote.

Loon, she said, hasn't pushed hard enough to cut government spending and hasn't been vocal enough in opposing the proposed Southwest Light Rail Line that would run from Eden Prairie to Minneapolis.

Sheila Kihne hustling from home to home in an Eden Prairie neighborhood last week. Tom Scheck/MPR News

The same-sex marriage vote, though, "was the straw that broke the camel's back," said Kihne, who used to support Loon.

"What this comes down to is put up or shut up," Kihne said last week about her decision to run as she door-knocked for votes in Eden Prairie. "I am running as a conservative in this race, both socially and fiscally."

Loon has also been talking to voters about her opposition to taxes and government spending.

She said she voted for same-sex marriage after talking it over with constituents, noting that a majority in her district voted against the proposed constitutional amendment to ban same-sex marriage in 2012.

She didn't regret the vote but added, "It was tough. I never had to make such a tough decision in the Legislature. I just think if people can understand the process, understand how much I wrestled with it, trying to be true to my own beliefs, to being true to what I felt my constituency was telling me. I did the best I could with a tough issue."

• May 29, 2014: House deputy minority leader faces primary challenge

Loon also dismissed Kihne's criticism that Republicans should have made deeper spending cuts when they controlled the Legislature, calling it "a little naive for someone to assume that you're going to win all (budget battles) when you have to work with a governor not of your own party."

Loon and her supporters are also taking aim at Kihne's past writings on her blog, saying she supported increasing taxes by letting federal tax cuts expire.

Kihne says her blog was intentionally provocative because she wanted to get a rise out of readers.

Republican delegates declined to endorse either candidate in March, setting up the primary battle that is now drawing tens of thousands of dollars in outside spending.

• July 23, 2014: Group aims to help Loon win primary

The House Republican Caucus is spending $25,000 on TV ads for Loon. The Minnesota Family Council has spent $32,000 in TV ads on Kihne's behalf and even more money on campaign mailings.

The family council is backing Kihne because it opposes Loon's stand on same-sex marriage, said spokeswoman Autumn Leva.

The group has not disclosed how much money it's spending on the race. Leva did not return calls to explain why the information was not included in recent campaign finance reports.

Meanwhile, another group backed by business groups and same-sex marriage supporters is backing Loon.

"Jenifer Loon, we know where she comes from. She's been a proven conservative," said Brian McClung with Freedom Minnesota PAC. "Sheila Kihne is a real question mark who has said some real questionable things online over the years."

Of the five Republicans who backed the same-sex marriage bill last year, Loon is the only one dealing with a primary challenge.

Rep. Pat Garofalo of Farmington easily won party endorsement and is not facing a primary. Andrea Kieffer of Woodbury is not seeking re-election. State Sen. Branden Petersen of Andover is not on the ballot until 2016.

Rep. David Fitzsimmons of Albertville is the only Republican who's paid a price so far. He opted to not run for re-election after losing his party's endorsement to Eric Lucero, who'd hammered Fitzsimmons over his support of the same-sex marriage bill.