The group that tried unsuccessfully to pass a constitutional amendment to ban same-sex marriage is asking the U.S. Supreme Court not to strike down a similar measure in California.

Minnesota for Marriage filed a friend-of-the-court brief urging the nation's highest court to overturn a ruling by the Ninth Circuit U.S. Court of Appeals that found California's marriage amendment to be unconstitutional.

The Minnesota group is arguing that if the rulings stands, the U.S. Supreme Court would "abruptly end the conversation about marriage" in other states.

"We are confident our brief will be helpful to the Supreme Court as it considers the constitutionality of California's Proposition 8," said Minnesota for Marriage spokeswoman Autumn Leva. "Like California, people in Minnesota have been debating public policies related to sexual orientation and marriage for some time, and we understand the importance of the court allowing public debate on these issues to continue."

California's law, like the one Minnesota voters rejected in November, defines marriage as a union between one man and one woman. About 30 other states have passed similar measures.

"Here in Minnesota, we believe the people will decide to maintain authentic marriage—between one man and one woman," Leva said. "Only the union of a man and a woman has the potential to produce new life. Government recognizes this unique difference and, for the sake of the kids involved, encourages men and women to commit to each other and their potential children by promoting authentic marriage."

The brief is authored by University of St. Thomas law school professor Teresa Collet, a Republican activist who has written extensively about abortion and marriage issues. Read the brief:

Minnesota for Marriage amicus brief by Baird Helgeson