Republican Sen. Lisa Murkowski of Alaska announced her support in June 2013 for same-sex marriage, becoming the third sitting GOP senator to back the right for gay and lesbian couples to marry. "I support the right of all Americans to marry the person they love and choose because I believe doing so promotes both values: it keeps politicians out of the most private and personal aspects of peoples' lives -- while also encouraging more families to form and more adults to make a lifetime commitment to one another," she wrote in an opinion piece on her website.
Former Maine Sen. Olympia Snowe says her views have shifted on same-sex marriage, and that she no longer supports the Defense of Marriage Act. "I think obviously this has evolved over time on the whole issue for the whole country and the nations," Snowe, a moderate Republican, told CNN. "We've seen a sea change in society's whole attitude on this particular issue and it's only natural for government to be responsive to those changes."
U.S. Sen. Mark Kirk, who is from Illinois, became the second sitting Republican senator to come out in support of same-sex marriage in a blog post in April 2013, writing, "Our time on this earth is limited, I know that better than most. Life comes down to who you love and who loves you back -- government has no place in the middle." He returned to work a few months before making a statement after taking time off to recover from a stroke.
Ohio Sen. Rob Portman made headlines on March 15, 2013 by coming out in support of same-sex marriage, a position he reached after his son told Portman and his wife that he was gay. He was the first sitting Republican senator to announce his support for gay marriage.
Former Vice President Dick Cheney came out in favor of same-sex marriage in 2009, but said the issue should be decided on a state-by-state basis. Cheney's daughter, Mary, is a lesbian and Republican activist who also advocates for same-sex marriage.
Former first lady Laura Bush voiced her support for gay marriage during a 2010 interview with Larry King.
Barbara Bush, left, daughter of former President George W. Bush, appeared in a YouTube video advocating for same-sex marriage in 2011.
Former Secretary of State Colin Powell came out in support of gay marriage in May 2012.
Meghan McCain, daughter of 2008 Republican presidential nominee John McCain, is a longtime supporter of same-sex marriage. She joined the the leadership committee of Young Conservatives for the Freedom to Marry in 2012 and previously participated in photo shoots for NOH8, a pro-gay marriage ad campaign protesting California's Proposition 8.
Cindy McCain, wife of John McCain, announced her support of gay marriage when she joined her daughter at a NOH8 photo shoot in 2010.
Former California Gov. Arnold Schwarzenegger fought to let same-sex couples get married in California while a ruling on Proposition 8, the voter-approved measure that made gay marriage illegal in the state that is now the focus of a case before the Supreme Court, was being challenged.
New York City Mayor Michael Bloomberg came out in support of gay marriage in 2005. He switched his party affiliation from Republican to independent in 2007.
More than 130 Republicans have signed on to a brief supporting gay marriage sent to the Supreme Court. Some of the most well-known signers include:
Ken Mehlman, Republican National Committee chairman from 2005 to 2007 and author of the brief
Mary Bono Mack, member of the House of Representatives from 1998 to 2013
Mary Cheney, director of vice-presidential operations for Bush-Cheney 2004 and former Vice President Dick Cheney's daughter
Clint Eastwood, actor, director and mayor of Carmel, Calif., from 1986 to 1988
David Frum, author and special assistant to the president from 2001 to 2002
Jon Huntsman, governor of Utah from 2005 to 2009, ambassador to China from 2009 to 2011 and Republican presidential candidate in 2012
Gary Johnson, Republican governor of New Mexico from 1995 to 2003 and Libertarian Party presidential nominee in 2012
Tom Ridge, governor of Pennsylvania from 1995 to 2001 and secretary of Homeland Security from 2003 to 2005
Christine Todd Whitman, governor of New Jersey from 1994 to 2001 and administrator of the Environmental Protection Agency from 2001 to 2003
Meg Whitman, Republican nominee for governor of California in 2010, who supported Proposition 8 during the campaign
Paul Wolfowitz, deputy secretary of defense from 2001 to 2005 and president of the World Bank Group from 2005 to 2007