A longtime Republican activist and former State Auditor is speaking out in favor of same-sex marriage and defending a GOP legislator who is under fire for supporting a proposal to allow gays and lesbians to marry.

In a column on the editorial pages of the St. Paul Pioneer Press Wednesday, Pat Anderson writes: "I applaud Republican State Sen. Branden Petersen for expressing his support of legislation that would extend the basic freedom to marry to same-sex couples in Minnesota, and I urge other Republican legislators and Minnesotans to join him."

Petersen, from Andover, has received scathing criticism from some corners of the Republican Party. But Petersen has also been praised, mostly from more libertarian-leaning Republicans.

Anderson, a former candidate for governor, is the first big-name Republican to support Petersen. Her announcement comes the day before advocates plan to unveil a bill to legalize same-sex marriage.

She called same-sex marriage "inevitable" in Minnesota and said that the GOP's position on the issue needs to evolve on the issue or the party risks alienating young people. She said the party's longstanding platform against same-sex marriage is antiquated and "misrepresents" the beliefs of many Republicans.

"I believe it is time for Minnesota state law to finally reflect the fact that marriage is about the love, commitment and responsibility that two people share," she said. "I cannot think of any valid reason for our state to continue to exclude same-sex couples from having the opportunity to marry and pursue happiness like anyone else."

Allowing all Minnesotans to marry the person they love should be a bedrock GOP principle, Anderson said.

"After all, protecting freedom and liberty — and removing unnecessary government intrusion from our lives — is, at its core, the conservative thing to do," she wrote.