Minnesota State Senator Branden Petersen is expected to sign on as the first Republican co-sponsor of a gay marriage bill.

“At this point, I am concerned about doing the right thing,” Petersen told the Star Tribune. “I have a certain amount of peace about that, and I will let the chips fall where they may.”

“It's only a matter of time before same-sex marriage is legal. I thought it was important to engage the issue now, and when we do it, do it right, and that there's some perspective from the people I represent in that.”

The position would be a reversal for Petersen, who voted in favor of a constitutional amendment limiting marriage to heterosexual couples. Minnesota became the first state to reject such an amendment last November.

At a Valentine's Day rally held at the Minnesota state capitol rotunda, Senator Scott Dibble pledged to introduce marriage equality legislation this week.

Dibble said he is willing to agree to Petersen's additions to the bill guaranteeing that any religious leader can choose not to wed gay couples and that children from such marriages have the same financial guarantees as those from other married couples in time of divorce.

Democrats regained control of the House and Senate in 2012. But with several Democrats publicly opposing the measure, Republican support is critical for passage.

“Republican support is something we want to make sure we have,” said Jake Loesch, a Republican and spokesman for Minnesotans United for All Families, the group pushing for the legislation. “Republicans are weighing this issue … As this conversation continues in the Legislature, there will be Republicans who will vote for marriage.”

Petersen, whose father-in-law has been in a relationship with another man for nearly 20 years, said he knows “there are other Republicans who are interested in supporting same-sex marriage.”