Politicians who've flip-flopped on same-sex marriage
Most recent polls have shown more Americans supporting same-sex marriage than opposing it, and majorities in Maine and Maryland voted to give gay and lesbians the right to marry last November at the ballot box. Politicians, too, perhaps sensing a new political environment, have started coming out in favor of marriage equality - at times reversing significantly from their past views on the subject.
Here, CBSNews.com rounds up some of same-sex marriage's most prominent political flip-floppers.
Joe Biden
"Men marrying men, women marrying women, and heterosexual men and women marrying another are entitled to the same exact rights, all the civil rights, all the civil liberties. And quite frankly, I don't see much of a distinction beyond that," said Biden, who had long supported civil unions but previously stopped short of explicitly endorsing same-sex marriage.
At the time, Biden's casual announcement caused something of a media firestorm: He had managed to both overshadow the president on the issue and force his hand on it. Later, Biden said he apologized to the president for the gaffe. But his change in position led to the president's own change of heart
President Obama
This was not Mr. Obama's first flip-flop on the issue: In 1996, as a candidate for the state Senate in Illinois, he offered "unequivocal" support for same-sex marriage before changing his position. As a candidate for president in 2008, Mr. Obama said he supported civil unions but not same-sex marriage.
Now, the president is vocal in his support for same-sex marriage, and his administration has declined to defend the Defense of Marriage Act (DOMA), a federal law that defines marriage as between one man and one woman and which will be challenged at the Supreme Court Wednesday.
Bill Clinton
Hillary Clinton
"That includes marriage," she said in the video. "That's why I support marriage for lesbian and gay couples. I support it personally and as a matter of policy and law."
Her announcement marked the latest shift over an issue on which she has been evolving for years. In 2007, Clinton rejected DOMA but then clarified through a spokesperson that she was objecting to the law's ban on federal recognition of same-sex marriages, not the idea that states have authority to determine the law independently.
Before her announcement, Clinton had long supported civil unions between same-sex couples, and she also backed the 2011 law that legalized same-sex marriage in New York State.
Dick Cheney
"As many of you know, one of my daughters is gay and it is something that we have lived with for a long time, in our family," he said in 2009. "I think people ought to be free to enter into any kind of union they wish. Any kind of arrangement they wish."
Cheney said then, as he had in the past, that he believes the issue should be determined by state legislatures.
Sen. Rob Portman
"I have come to believe that if two people are prepared to make a lifetime commitment to love and care for each other in good times and in bad, the government shouldn't deny them the opportunity to get married," he wrote, explaining his decision in an op-ed this month.
"My position on marriage for same-sex couples was rooted in my faith tradition that marriage is a sacred bond between a man and a woman. Knowing that my son is gay prompted me to consider the issue from another perspective: that of a dad who wants all three of his kids to lead happy, meaningful lives with the people they love, a blessing Jane and I have shared for 26 years."
Democratic senators
As Democrats in conservative-friendly states, their support signals a sense that backing same-sex marriage is no longer considered a major political liability.
