(CNN) - As the Supreme Court gets ready to hear cases on same-sex marriage next month, dozens of high-profile Republicans have signed onto a brief in a show of support for gay couples to legally wed.
The amicus or “friend of the court” legal brief, first reported by the New York Times, includes signatures by close advisers to former President George W. Bush as well as former governors and two members of Congress.
Next month, the Supreme Court will hear two separate oral arguments on challenges to Proposition 8, the voter-approved same-sex marriage ban in California, as well as the Defense of Marriage Act (DOMA), a 1996 congressional law that says for federal purposes, marriage is defined as only between one man and one woman.
Because of DOMA, certain benefits–such as federal tax, Social Security, pension, and bankruptcy benefits–do not apply to gay and lesbian couples legally married in those states that allow such unions.
Ana Navarro, Republican strategist and CNN contributor, was one of the signatories of the amicus brief, which is aimed to influence conservative justices on the high court. As of Monday night, the brief had 75 signatures.
"I'm not going to discuss the brief in respect to the Court, but on the issue itself, equality is something I deeply believe in," Navarro said. "Denying that the issue of marriage equality has changed, is being on the wrong side of history and on the wrong side of love and commitment."
The legal brief is at odds with the Republican Party's platform, which opposes same-sex marriage and defines marriage as a union between a man and a woman.
The legalization of same-sex marriage in nine states (and Washington, D.C.) has been "an assault on the foundations of our society," according to the GOP 2012 platform. Same-sex marriage, the platform reads, challenges an "institution which, for thousands of years in virtually every civilization, has been entrusted with the rearing of children and the transmission of cultural values."
But the Republican opposition effort, in part spearheaded by former RNC Chairman Ken Mehlman, who also served in the Bush administration, argues that same-sex marriage aligns with the party's family values by creating a two-parent home for children. It also promotes conservative staples such as "limited government and maximizing individual freedom," the Times reports.
Former presidential candidate Jon Huntsman is one of the names on the list, a Republican source familiar with the brief confirmed. While he stated support for civil unions during his unsuccessful White House bid for the 2012 election, he did not come out in favor of same-sex marriage until he penned an op-ed last week for the American Conservative Union.
"Conservatives should start to lead again and push their states to join the nine others that allow all their citizens to marry," Huntsman wrote. "There is nothing conservative about denying other Americans the ability to forge that same relationship with the person they love."
Other names inked on the brief, according to the Republican source, include former California gubernatorial candidate Meg Whitman, Florida Rep. Ileana Ros-Lehtinen, Rep. Richard Hanna of New York, former Rep. Deborah Pryce of Ohio, former Bush Commerce Secretary Carlos Gutierrez, former Bush National Security Adviser Steve Hadley and former Deputy Attorney General James B. Comey.
Interestingly, certain top Republicans who have publicly expressed support for same-sex marriage–such as former first lady Laura Bush, former Vice President Dick Cheney, and former Secretary of State Colin Powell–were not on the list, the Times reported.
READ MORE: Laura Bush: Take me out of pro-gay marriage ad
Recent polling reflects the trend that same-sex marriage is starting to gain support, even among Republicans. According to CBS News Poll released earlier this month, 54% of Americans, including nearly a third of Republicans, said same-sex couples should have the legal right to marry, while 39% said they should not be allowed to do so.
However, a stronger majority–61%–said that decision should be left to the states, while 29% said the federal government should have that authority.
The issue is widely expected to see intense debate this year as the Supreme Court makes decisions on DOMA and Proposition 8. The Obama administration set the scene for the upcoming showdown when it declared DOMA unconstitutional last week.
"Moral opposition to homosexuality, though it may reflect deeply held personal views, is not a legitimate policy objective that can justify unequal treatment of gay and lesbian people" contained in the DOMA law, Solicitor General Donald Verrilli said in the Justice Department's legal brief.
- CNN's Paul Steinhauser, Kevin Bohn, Bill Mears, and Ashley Killough contributed to this report.