Some were disturbed by the president's position.
"I don't agree with it. It's an abomination," said Previn McCray, manager of Philly Styles Hair Studio, a barbershop on 11th and Chestnut Streets. "It's not in the Bible, not in the Koran, not in any religious book. Obama hurt my feelings on that one."
But McCray, 43, said he understands why long-term gay couples might want the kinds of legal protections that heterosexual couples have. "If you have established something, why shouldn't you be able to keep it?"
Stylist Rick Champagne, 41, was less ambivalent. "I don't have nothing against gay people. Half my clientele is gay, but we're not made to connect that kind of way."
Patrons at Woody's on 13th Street watched Obama's interview on the television above the bar. Chris Tadeo, 80, praised the president and talked about how much he'd love to marry his longtime partner, Wayne Marquardt. They've lived together for 32 years in Philadelphia.
"We consider that we're married, and we love each other," Tadeo said. "But we'd like to be law-abiding."
At the office of Philadelphia Gay News, publisher Mark Segal saw Obama's interview and immediately told the editor to hold the front page because the paper would need a new lead story and headline.
"The president was very brave and very bold. He spoke from principle rather than politics," Segal said. "It was historic - it sets a new bar."
The staff was especially touched, he said, "by the way he talked about it, within the framework of family and values."
The president's position is not going to persuade citizens like those who voted in North Carolina this week to pass an amendment to the state constitution banning gay marriage, said Ted Martin, executive director of Equality Pennsylvania, the state's LGBT advocacy organization.
And politically, it is unlikely to nudge the solidly conservative Republican majority in Harrisburg, led by Gov. Corbett, who has repeatedly affirmed his opposition to gay marriage. (Corbett declined to comment on the president's remarks Wednesday.)
Nevertheless, Martin said, the president's words will have an impact. "It elevates the discussion," he said.
"This is a watershed moment for gay equality," said Malcolm Lazin, executive director of the Equality Forum, an international LGBT civil rights organization. "The president is sending a message that can only accelerate the inevitable, which is overwhelming acceptance of same-sex marriage. We're really thrilled he has used the bully pulpit to promote it."
Opponents of gay marriage, such as Michael Geer of the Pennsylvania Family Institute, see the president's statement more cynically.
"Since running for office in 2008, he has said the sacred institution of marriage should be reserved for a man and a woman. Those were words of political expediency," Geer said. "Now he has said what he truly believes."
Geer e-mailed a copy of written responses that Obama sent to a Chicago reporter in 1996 saying he favored same-sex marriage and would "fight efforts to prohibit such marriages."
Geer challenged Obama's sincerity in explaining his position as an "evolution."
"It's an evolution that just took him back to his starting point," Geer said.
In New Jersey, the president's statement may further agitate an already rollicking political debate on the issue.
Democratic leaders in New Jersey's Legislature made gay marriage their top priority this year, numbering the bill symbolically as "1" in both the Assembly and Senate, which are controlled by Democrats. In February, both chambers passed a bill that would have legalized same-sex marriage, two years after a similar bill failed in the Senate.
But Republican Gov. Christie vetoed it, arguing that residents should vote on the issue directly through a referendum. Christie also said he'd prefer instead to strengthen the civil unions law that has been on the books since 2007. A spokesman for the governor Wednesday said his position had not changed.
Daniel Weiss, 47, an Asbury Park lawyer, said a civil union didn't help him when his partner of six years was hit by a car. Hospital officials would not let Weiss sign a form allowing doctors to perform emergency brain surgery. Grant's sister had to drive up from Delaware to sign the document, he said. Officials also denied Weiss access to Grant's room and would not let him retrieve Grant's health insurance card from his wallet.
"If I, a lawyer for two decades, can't articulate to a neurosurgeon why a civil union is equal to a marriage, then it's not" equal, Weiss said. "Words do matter. . . . It has to be one of the most vicious forms of discrimination I can think of, when you can't even speak up for your partner's medical decisions" in an emergency, he said.
Asked about Obama's announcement Wednesday, Weiss called it "a huge step forward."
Senate President Stephen Sweeney (D., Gloucester), who led the push for the bill in the Senate, said Wednesday that Christie is "on the wrong side of history," and added, "We passed it early, and we intend to override the governor on this."
Sweeney argued that some Republican legislators voted against the bill or abstained because they feared reprisals from their own party, including primary challenges.
Supporters of the bill need three additional votes in the Senate and a dozen in the Assembly to override Christie's veto.
In the past, Christie has said that he falls in line with Obama's views on gay marriage. "He can't hide behind that anymore," Sweeney said.
For many same-sex couples living in states where they cannot marry, the president's support provides comfort as well as hope.
Carrie Jacobs, the director of the Attic Youth Center, said she was deeply moved, watching Wackwitz and the other students cheering and raising their arms with joy as they listened to the president Wednesday: "It gives very young kids hope that they will have the same freedom that everybody has."
But for Jacobs and the partner she has lived with and raised two children with over the last 28 years, the joy is more muted. They could go to another state to marry, she says, but have decided to wait. "When it's OK everywhere, then we'll get married," she said. "We just hope it happens in our lifetime."
Contact Melissa Dribben at 215-854-2590 or firstname.lastname@example.org, or follow on Twitter @dribbenonphilly.