On the fence no longer, President Obama declared his unequivocal support for gay marriage Wednesday, a historic announcement that gave the polarizing social issue a more prominent role in the 2012 race for the White House.
The announcement was the first by a sitting president, and Republican challenger Mitt Romney swiftly disagreed with it. "I believe that marriage is between a man and a woman," he said while campaigning in Oklahoma.
Romney also opposes most same-sex civil unions, saying they resemble marriage too much, but he has said domestic partnerships with more limited benefits would be acceptable.
Gay rights advocates cheered Obama's declaration, which they had long urged him to make.
But in a statement released Wednesday night, the Catholic Archdiocese of Washington said the complementarity of man and woman is key to the meaning of marriage and that it supports efforts by those who wish to uphold the traditional meaning of marriage.
Obama once opposed gay marriage but more recently had said his views were "evolving."
In an interview with ABC in which he blended the personal and the presidential, Obama said "it wouldn't dawn" on his daughters, Sasha and Malia, that some of their friends' parents would be treated differently than others. He said he also thought of aides "who are in incredibly committed monogamous same-sex relationships who are raising kids together."
Obama added that he thought about "those soldiers or airmen or Marines or sailors who are out there fighting on my behalf and yet feel constrained, even though now that 'don't ask, don't tell' is gone, because they're not able to commit themselves in a marriage."
The president said he was taking a personal position. Aides said the president's shift would have no impact on current policies and that he continues to believe that marriage is an issue best decided by states.
"I have hesitated on gay marriage in part because I thought that civil unions would be sufficient," Obama said in the interview.
He added, "I was sensitive to the fact that for a lot of people the word 'marriage' was something that evokes very powerful traditions, religious beliefs and so forth."
Now, he said, "it is important for me personally to go ahead and affirm that same-sex couples should be able to get married."
Vice President Biden said in an interview Sunday that he is completely comfortable with gays marrying, a pronouncement that instantly raised the profile of the issue.
Tuesday, voters in North Carolina -- a potential battleground in the fall election -- approved by a wide margin an amendment to the state constitution affirming that marriage may only be a union of a man and a woman.
Several of the president's biggest financial backers are gay, and some have prodded him publicly to declare his support for same-sex marriage.
Senior administration officials said Obama came to the conclusion earlier this year that gay couples should have the right to legally marry and had planned to make his views known publicly before the Democratic National Convention in early September.
In a national survey released earlier this month, Gallup reported 50 percent of those polled said gay marriage should be legal, and 48 percent were opposed. Democrats favored gay marriage by a ratio of roughly 2-1, while Republicans opposed it by an even bigger margin. Among independents, 57 percent expressed support, and 40 percent were opposed.
Whatever the polls, the political crosscurrents are tricky, and administration officials conceded as much.
Some top aides argued that gay marriage is toxic at the ballot box in competitive states like North Carolina and said the vote there this week shows that opposition to the issue is a rallying point for Republicans.
Shifting his emphasis, even briefly, could open Obama up to Republican criticism that he is taking his eye off the economy, voters' No. 1 issue.
Other Democratic supporters claim Obama's decision could energize huge swaths of the party, including young people and give Democrats a huge fundraising boost from wealthy gay donors.
He also could appeal to independent voters, they noted.
By day's end Wednesday, the Obama campaign had emailed a clip of the interview and a personal statement from the president to its vast list of supporters, drawing attention to his stance.
Acknowledging that his support for same-sex marriage may rankle religious conservatives, Obama said he thinks about his faith in part through the prism of the Golden Rule -- treating others the way you would want to be treated.
"That's what we try to impart to our kids, and that's what motivates me as president, and I figure the most consistent I can be in being true to those precepts, the better I'll be as a dad and a husband and hopefully the better I'll be as president," Obama said.
Six states -- including New York -- and the District of Columbia allow same-sex marriages. In addition, two other states have laws that are not yet in effect and may be subject to referendums.
Gov. Andrew M. Cuomo called Obama's comments, which came 11 months after New York joined other states in legalizing same-sex marriages, "a major advancement for equal rights in this country."
"I applaud the president's courage. I believe it will be respected by the people of this country. I think it's going to be a great boost for marriage equality," Cuomo told reporters in the Capitol's Red Room.
Tom Precious of The News Albany Bureau contributed to this report.