He gave no speech, issued no call to action. He spoke of changing alongside the nation's people, not of leading them into uncharted territory. He made sure to say what so many so passionately believe _ that states should decide such issues on their own.
The first black president becoming the first president to speak out for a minority denied the right to marry is undoubtedly a powerful political moment. But a significant cultural milestone? A nation full of straight people at ease among openly gay co-workers, relatives and sitcom characters may already have passed Barack Obama by.
It is a truism, but it's worth saying nonetheless: Politics lags behind culture, especially Hollywood's version of it.
The president himself describes his change of position on gay marriage as several steps behind his 10- and 13-year-old daughters and the college students he frequently encounters _ even young Republicans _ who already see treating gays equally as no big deal.
And this is the societal backdrop against which he made his pronouncement Wednesday:
After the military's "don't ask, don't tell" policy was lifted last year, gay and lesbian soldiers who came out to their comrades in arms reported being met with shrugs. High school students hang out in gay-straight alliance groups. Celebrities line up to condemn bullying of gay youth. On TV shows like "Modern Family," `'Grey's Anatomy" and "Smash," gay characters get married, adopt children and kiss on screen, to little public outcry; within the story lines, they're just part of the cast.
Vice President Joe Biden, whose weekend declaration that he's "absolutely comfortable" with gay marriage nudged Obama to take on the politically hazardous subject, credited the 1998-2006 TV sitcom "Will & Grace" with doing "more to educate the public than almost anything anybody's done so far." The show featured two main characters _ a heterosexual female and a gay male _ trying to understand their friends, their challenges and their lives.
"People fear that which is different," Biden said. "Now they're beginning to understand."
Such programming, of course, is primarily aimed at the under-30 viewers whom advertisers covet, not the older folks who are more likely to be appalled by scenes of gay romance.
"The younger age group believes this is fine," said Kathleen Hall Jamieson, an expert on political rhetoric. "The problem is, it's the older age group that votes."
Obama's pronouncement, in an ABC interview, doesn't mean same-sex marriage will suddenly become widespread across the country. Indeed, Obama spoke up the day after North Carolina voters overwhelmingly passed a constitutional amendment that defines marriage as solely between a man and a woman. It became the 30th state to approve such a measure. Brian Brown, president of the National Organization for Marriage, said that record disproves the theory "that same-sex marriage is inevitable."
Yet six states and the District of Columbia issue marriage licenses to gay couples. Nine allow civil unions or have domestic partnership laws that provide equivalent rights. Maine, Maryland and Washington state lawmakers have moved toward gay marriage, with the final outcomes possibly to be decided by voters in November.
Sarah Warbelow, who's spent four years pushing the marriage issue state by state for the Human Rights Campaign, said the president's show of support "is bound to change hearts and minds." "We're absolutely thrilled," she said.
Taken as a whole, the nation is almost evenly divided on the question of same-sex marriage, with conservatives and Republicans strongly opposed and Democrats and independents mostly in favor. But polls show support's been on an upward trend for years, and the opposition clusters among Americans over age 55.
Six out of 10 of those who are younger than that favor gay marriage, according to an AP-National Constitution Center poll.
And acceptance of gays is wider than acceptance of gay marriage. The numbers go up, for example, when you include those who are OK with granting legal status to gay couples so long as it's called something like a civil union instead of a marriage _ the position Obama had previously taken, as did President George W. Bush.
But relationships so routine they often go barely noticed in everyday life still provoke fervent argument when they come under the glare of court challenges and the endless partisan fights of the culture wars. Particularly contentious: When the question of gay rights intersects with children or with government benefits and protections.
Should gays and lesbians be allowed to adopt children? In 18 states they can, and in some others the decision is left up to local judges.
Should they be protected from job discrimination? Twenty-one states say yes.
And what about the Boy Scouts' ban on gay leaders? Transgendered Girl Scouts? The idea that gay marriage will surely lead to further loosening of what society will accept?
Gay rights are regularly sliced into multiple wedge issues at election time. How gay marriage is folded into the presidential campaign will be a good barometer for how far America's views have shifted _ perhaps far more than Obama's statement itself, though its appearance as the general election season begins is hard not to notice.
And in a society still divided, it cuts both ways. Ralph Reed, chairman of the conservative Faith & Freedom Coalition, said Obama had just handed presumptive Republican nominee Mitt Romney a choice culture issue.
"Twenty-four hours ago, we were talking about what Romney had to do to get social conservatives on board," Reed said Wednesday in a telephone interview. "Now, they're scrambling for a seat in first class."
Romney opposes gay marriage but says states should be able to decide whether to offer limited legal rights to same-sex couples. "This is a very tender and sensitive topic," Romney said Wednesday.
It's also a topic that can fire up subsets of voters without distracting most from the U.S. economic troubles. Gay rights issues are cited as the nation's most important problem by 1 percent or less of the population, according to Gallup.
As he presented his evolving view, Obama treaded cautiously. He acknowledged that many Americans have religious objections and said that influenced his decision not to endorse gay marriage earlier. He spoke in personal, not political, terms, noting his experience with the gay parents who serve on his staff or who are raising friends of his daughters, Sasha and Malia.
The girls would never imagine "that somehow their friends' parents would be treated differently," Obama said. "It doesn't make sense to them and, frankly, that's the kind of thing that prompts a change in perspective."
Presidents determined to push the nation forward on great social questions give rousing addresses from their bully pulpits. Franklin Roosevelt laid out four freedoms _ freedom of speech and worship, and freedom from want and fear _ as American ideals worth fighting for in Europe and ensuring for suffering people at home. Lyndon Johnson declared that "we shall overcome" must become the conviction of all conscientious Americans, not only civil rights marchers.
But for Barack Obama on Wednesday, it was different. Instead of proposing, he concurred. Instead of advocating, he acknowledged. Instead of saying, "We must," he was saying, in effect, "We already are."
New York Mayor Michael R. Bloomberg was quick to mark it a major turning point in history. "No American president has ever supported a major expansion of civil rights that has not ultimately been adopted by the American people," he said.
Others weren't so certain.
"He's not waving the flag. He's nodding his head," said political historian Evan Cornog, dean of Hofstra University's School of Communication, who has studied how presidents build their own story lines.
When historians look back in 50 years or so on the struggle for gay rights and its place in American culture, Cornog said, "It may be that `Modern Family' means more than Obama's statement."