By coming out as gay while still an active NBA player, Jason Collins breaks one of the last remaining barriers for gays and lesbians in era of constant political gains and ever-growing public acceptance.
In most other realms of public life — including the military, Congress, the corporate boardroom — gays have been taking their place as equals. Until Monday, however, no male athlete had come out as gay while still an active player on any team in the four major North American pro sports leagues.
"Today's announcement again shows that gay Americans are our teachers, police officers, nurses, lawyers and even our professional athletes," said the president of the largest national gay-rights group, Chad Griffin of the Human Rights Campaign.
"We contribute to every aspect of our American community and deserve the same equal rights as every American," he said.
Beyond sports, the most dramatic barometer of shifting attitudes has been public opinion on same-sex marriage. The latest Gallup Poll on that issue pegged national support at 53 percent, up nearly twofold from 27 percent in 1996.
That change has been reflected in the political arena.
With a key vote in the state Senate last week, Rhode Island put itself on track to become the 10th state to legalize same-sex marriage. Bills proposing to take the same step are pending in Minnesota, Delaware and Illinois.
Gay-rights supporters hope the trend will be reflected in rulings by the U.S. Supreme Court, expected in June, on whether the federal government should recognize same-sex marriages and on whether a ban on such marriages in California should be struck down.
Pollsters say there are two main reasons why many Americans who formerly opposed gay marriage are now supporting it. Many say it's because they know someone who is gay — a family member, friend or acquaintance — while others say their views evolved as they thought more about the issue.
Public opinion also played a role in the 2011 repeal of the "don't ask, don't tell" policy that had barred gays and lesbians from serving openly in the military. By the time that top military commanders and most members of Congress joined the repeal bandwagon, a majority of the public already was supporting a change in the policy.
In Congress, there are now a record seven openly gay or bisexual members, including Wisconsin Democrat Tammy Baldwin, the first openly gay U.S. senator, and Rep. Jared Polis, D-Colo., who is raising a son with his partner. Sympathetic gay characters abound on popular TV shows, in films and in comic books.
In America's workplaces, the picture is somewhat mixed. A majority of states have no laws banning job discrimination on the basis of sexual orientation. And yet, most major corporations have equal-opportunity policies for gays, often including extension of domestic-partnership benefits.
According to the Human Rights Campaign, 13 major employers earned a perfect score in 2001 when it started an index to rate businesses on gay-friendly employment practices. This year, 252 businesses received perfect scores.
Even with all the momentum for various gay-rights advances, public opinion on some fundamental questions about homosexuality remains markedly divided.
According to the General Social Survey, conducted annually by independent research organization NORC at the University of Chicago, disapproval of gay sex peaked in 1987, when 76 percent of Americans thought sexual relations between adults of the same sex was always wrong.
In the 2012 survey, which involved interviews with 1,974 U.S. adults, 43 percent felt that way, while just as many said gay sex was not morally wrong at all. African-Americans were less accepting of homosexuality than whites or Hispanics, with 58 percent of the black respondents saying same-sex sexual relations are always wrong.
Nonetheless, the Rev. Al Sharpton, a leading black civil rights activist, was among those welcoming the announcement by Collins, who also is black.
"I call on others in the civil rights community and the African-American leadership of all fields to embrace this development," Sharpton said. "We can't be custodians of intolerance and freedom fighters at the same time."
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