WASHINGTON — For 15 minutes in the Oval Office the other day, one of President Obama’s top campaign lieutenants, Steve Hildebrand, told the president about the “hurt, anxiety and anger” that he and other gay supporters felt over the slow pace of the White House’s engagement with gay issues.

But on Monday, 250 gay leaders are to join Mr. Obama in the East Room to commemorate publicly the 40th anniversary of the birth of the modern gay rights movement: a police raid on the Stonewall Inn, a gay bar in New York. By contrast, the first time gay leaders were invited to the White House, in March 1977, they met a midlevel aide on a Saturday when the press and President Jimmy Carter were nowhere in sight.

The conflicting signals from the White House about its commitment to gay issues reflect a broader paradox: even as cultural acceptance of homosexuality increases across the country, the politics of gay rights remains full of crosscurrents.

It is reflected in the surge of gay men and lesbians on television and in public office, and in polls measuring a steady rise in support for gay rights measures. Despite approval in California of a ballot measure banning same-sex marriage, it has been authorized in six states.

Yet if the culture is moving on, national politics is not, or at least not as rapidly. Mr. Obama has yet to fulfill a campaign promise to repeal the policy barring openly gay people from serving in the military. The prospects that Congress will ever send him a bill overturning the Defense of Marriage Act, which defines marriage as between a man and a woman, appear dim. An effort to extend hate-crime legislation to include gay victims has produced a bitter backlash in some quarters: Senator Jim DeMint, Republican of South Carolina, sent a letter to clerics in his state arguing that it would be destructive to “faith, families and freedom.”

“America is changing more quickly than the government,” said Linda Ketner, a gay Democrat from South Carolina who came within four percentage points of winning a Congressional seat in November. “They are lagging behind the crowd. But if I remember my poli sci from college, isn’t that the way it always works?”

Some elected Democrats in Washington remain wary because they remember how conservatives used same-sex marriage and gay service in the military against them as political issues. The Obama White House in particular is reluctant to embrace gay rights issues now, officials there say, because they do not want to provide social conservatives a rallying cry while the president is trying to assemble legislative coalitions on health care and other initiatives.

Tony Perkins, the president of the Family Research Council, a group that opposes gay rights initiatives, said Mr. Obama’s reluctance to push more assertively for gay rights reflected public opinion.

“He’s given them a few minor concessions; they’re asking for more, such as ‘don’t ask, don’t tell’ being repealed,” Mr. Perkins said. “The administration is not willing to go there, and I think there’s a reason for that, and that is because I think the American public isn’t there.”

Conservative Democrats have at best been unenthusiastic about efforts to push gay rights measures in Congress; 30 Democrats voted against a bill prohibiting discrimination based on sexual orientation that passed the House in 2007. (It died in the Senate.) And a half-dozen Democrats declined requests to discuss this issue, reflecting what aides called the complicated politics surrounding it.

Still, there are signs that the issue is not as pressing or toxic as it once was. “I don’t think it’s the political deal-breaker it once was,” said Dave Saunders, a southern Virginia Democratic consultant who has advised Democrats running for office in conservative rural areas. “Most people out here really don’t care because everybody has gay friends.”

Interviews with gay leaders suggest a consensus that there has been nothing short of a cultural transformation in the space of just a few years, even if it is reflected more in the evolving culture of the country than in the body of its laws.

“The diminution of the homophobia has been as important a phenomena as anything we’ve seen in the last 15 years,” said Representative Barney Frank, Democrat of Massachusetts, who is gay.

Democrats now control the White House and both houses of Congress for the first time since 1994, increasing the chances of legislative action. Mr. Frank said that over the next two years, he expected Congress to overturn the ban on gay service in the military, pass legislation prohibiting discrimination against hiring gay workers, and extend the hate-crime bill to crimes involving gay couples.

There is also an emerging generational divide on gay issues — younger Americans tend to have more liberal positions — that has fueled what pollsters said was a measurable liberalization in views on gay rights over the past decade.

A New York Times/CBS News poll last spring found that 57 percent of people under 40 said they supported same-sex marriage, compared with 31 percent of respondents over 40. Andy Kohut, the president of the Pew Research Center, said the generational shift was reflected in his polling, in which the number of Americans opposing gay people serving openly in the military had dropped to 32 percent now from 45 percent in 1994.

David Axelrod, a senior Obama adviser, said, “You look at polling and attitudes among younger people on these issues are startlingly different than older people.”

“As generational change happens,” Mr. Axelrod added, “that’s going to be more and more true.”

In the view of many gay leaders, the shifts in public attitude are a validation of the central political goal set by the dozens of gay liberation groups that sprouted up in cities and on college campuses in the months after the Stonewall uprising: to have gay men and lesbians who had been living in secret go public as a way of dealing with societal fear and prejudice.

But there is considerable evidence that this is still an issue that stirs political concerns. Gay leaders have increasingly complained about what they call Mr. Obama’s slow pace in fulfilling promises he made during his campaign. Some boycotted a Democratic Party fund-raiser recently to show their distress.

“I have been really surprised how paralyzed they seem around this,” said Richard Socarides, who was an adviser to President Bill Clinton on gay issues.

Mr. Hildebrand did not respond to calls and e-mail messages asking about his encounter with Mr. Obama, which he described in a private e-mail forum for gay political leaders. (The meeting was confirmed by senior White House officials.)

Still, David Mixner, a longtime gay leader, said he was struck by how things had changed.

“Listen,” Mr. Mixner said, “in 1992, what we were begging Bill Clinton about — literally — about whether he was going to say the word ‘gay’ in his convention speech. Even say it. We had to threaten a walkout to get it in.”