A group opposing same-sex marriage is fundraising based on GOP Sen. Branden Petersen's declaration that he would consider co-sponsoring a bill to legalize same sex marriage.

"A Stronger Minnesota holds "Republicans" like Petersen accountable for straying from traditional Minnesota values," Stronger Minnesota president Andy Parrish said in an email to supporters.

The Star Tribune first reported that Petersen, R-Andover, is prepared to sign onto the proposal that would legalize same-sex marriage. Petersen, a first-term Senator who previously served in the House, is the first Republican to announce support for the measure.

"People like Petersen don't really believe that God knew what He was doing when He designed marriage. People like Peterson believe they can build a better version then God was able to," Parrish wrote in his fundraising email.

Parrish was the deputy campaign manager for Minnesota for Marriage, the unsuccessful 2012 campaign to pass a constitutional amendment defining marriage as only the union of one man and one woman.

The group pushing to legalize same sex marriage also sent out a fundraising plea in the wake of Peterson's announced support.

Baird Helgeson contributed to this blog post.