Both President Barack Obama's administration and a group of Republican officials have filed briefs with the U.S. Supreme Court calling for marriage to be redefined to include same-sex partners.

"Like a lot of the country, my views have evolved on this from the first day I set foot in Congress," said former U.S. Representative Deborah Pryce (R-Ohio).

On Feb. 25, a group of over 70 Republican leaders and public figures filed a "friend of the court" brief on the upcoming Supreme Court case regarding California's Proposition 8, a state constitutional amendment that banned gay marriage within California.

The brief's position contradicts the official Republican Party platform, which reaffirmed its stance that marriage is "a union of one man and one woman" in Aug. 2012.

The brief was organized by Ken Mehlman, former chairman of the Republican National Committee, and will be filed on March 1.

The Obama administration also voiced its support of same-sex "marriage" through a brief opposing the Defense of Marriage Act, a 1996 federal law that affirmed marriage as a union between a man and a woman for purposes of federal grants, benefits and tax information.

Oral arguments in both cases will be heard before the Supreme Court in March 2013 following challenges to their constitutionality. The court cases are expected to be "landmark" decisions that will define the way marriage is understood within the United States.

The Department of Justice, the branch of the president's administration filing the brief, claimed that the Defense of Marriage Act was "discriminatory" against a "discrete minority class of homosexuals." The department claimed that homosexual individuals have been historically discriminated against, that they are "a minority group with limited political power."

In addition, it asserted that an "expert consensus" exists saying that children of same-sex parents do not differ from biological and opposite-sex parents. This claim contradicts a study published by University of Texas-Austin researcher Mark Regnerus in 2012 noting various disadvantages faced by children raised by same-sex parents.

The department added that the federal government does not have an interest in promoting traditional marriage, even if it does value the traditional institution.

Quoting decisions by other courts, the brief stated that the "ancient lineage of a legal concept does not give a law immunity from attack" and claimed that the federal interest in protecting a traditional view of marriage cannot be achieved through the Defense of Marriage Act "because the decision of whether same-sex couples can marry is left to the states."

Those who oppose a redefinition of marriage argue that governments have traditionally been involved in regulating marriage as the union of one man and one woman because this is the only type of union that can produce children.

They say that government has an interest in promoting the well-being of society's future generations by encouraging stable households in which children are raised by their biological parents whenever possible.

In May 2012, President Obama announced that his positions on "gay marriage" had "evolved" and that he supported the recognition of same-sex partnerships as marriage, contradicting his statements during the 2008 election.

Republicans who signed the brief opposing Proposition 8 referenced a shift in popular opinion as a motivating factor for their change in position, despite recent moves in numerous states to reaffirm marriage as the union of man and woman.

Steve Schmidt, a signer of the brief and former senior advisor to John McCain's 2008 presidential campaign, argued that the "die is cast on this issue."

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