President Obama has publicly declared his support for same-sex marriage, becoming the first U.S. president to do so. In an interview with ABC News, Obama said his stance had partially evolved through the indirect influence of his daughters.

President Obama: “Malia and Sasha, it wouldn’t dawn on them that somehow their friends’ parents would be treated differently. It doesn’t make sense to them. And frankly, that’s the kind of thing that prompts a change of perspective.”

Obama chose to address the issue days after Vice President Joe Biden declared his support for same-sex marriage, which had set off new calls for Obama to clarify his stance. Despite offering his personal endorsement, Obama said he still believes same-sex marriage is an issue of “states’ rights” — to be decided by states, not by the federal government. Just this week, voters in North Carolina passed a constitutional amendment banning same-sex marriage, while in Colorado, Republicans blocked a same-sex civil unions bill in the state House, prompting Gov. John Hickenlooper to convene a special session beginning on Friday.