Dissecting President Obama's 'Evolution' on Gay Marriage

March 25, 2013 — -- The Supreme Court will hear arguments in two landmark cases on same-sex marriage this week, nearly 11 months after President Obama first announced his support of marriage for same-sex couples, a decision he reached as part of an "evolution" over the years.

In an interview with ABC News' Robin Roberts in May, President Obama stated his personal support for same-sex marriage, becoming the first president to back marriage publicly for gay and lesbian couples.

"For me, personally, it is important for me to go ahead and affirm that I think same-sex couples should be able to get married," Obama told Roberts in May of 2012.

While voicing his support at the time, the president said that he had no intention to "nationalize" the issue and hoped it would be left up to the states.

"I have to tell you that part of my hesitation on this has also been I didn't want to nationalize the issue," he told Roberts. "There's a tendency when I weigh in to think suddenly it becomes political and it becomes polarized. What I'm saying is that different states are coming to different conclusions. But this debate is taking place, at a local level. And I think the whole country is evolving and changing."

But less than a year later, the Supreme Court is taking up two potentially transformative cases on the issue of gay marriage at a time when public support for same-sex marriages has jumped. An ABC News-Washington Post poll released last week found that 58 percent of Americans support legalizing marriage for gay and lesbian couples, and in the past month, two heavy hitters in politics -- former Secretary of State Hillary Clinton and Republican Sen. Rob Portman of Ohio -- announced their support of same-sex marriage.

In an interview with ABC News' George Stephanopoulos earlier this month, the president said he hopes the Supreme Court will grant same-sex couples the right to marry. When asked whether he could think of a compelling reason for states to bar same-sex marriage, he said "I can't, personally. I cannot."

"Ultimately, I think that same-sex couples should be able to marry. That's my personal position," Obama told Stephanopoulos. "My hope is that -- the court looks at the evidence and -- and in the California case, for example, the only reason presented for treating gays and lesbians differently was, 'Well, they're gay and lesbian.' There wasn't a real rationale beyond that. In fact, all the other rights ... responsibilities of a civil union were identical to marriage.

"It's just you couldn't call it marriage. Well, at that point, what you're really saying is, 'We're just going to treat these folks differently because of who they are.' And I do not think ... that's who are as Americans. And ... frankly, I think, American attitudes have evolved, just like mine have, pretty substantially and fairly quickly, and I think that's a good thing."

The Supreme Court Tuesday will consider Proposition 8, the California ballot initiative that defines marriage as being between a man and a woman. The court will hear arguments Wednesday on a federal law, the Defense of Marriage Act (DOMA), which issues the same definition of marriage as Prop 8 but also denies federal benefits to same-sex couples who are legally married in their states.