Most countries that allow gay marriage, he added, lifted their military bans on gays first.

Today the military, tomorrow the marriage altar?

In an era when gay Americans have seen stunning progress and many setbacks in the quest for equality under the law, many believe 2010 will go down in history as a watershed that will lead inexorably to more legal rights.

Saturday's vote in the Senate to allow the repeal of the federal law banning gays from openly serving in the military is "one of the greatest, if not the greatest, victory in the history of the movement for gay and lesbian equality," said Aaron Belkin, director of the Palm Center, a University of California-Santa Barbara think tank that studies the issue of gays in the military.

"Going back thousands of years, the marker of a first-class citizen has always been someone who's been allowed to serve in the military."

Most countries that allow gay marriage, he added, lifted their military bans on gays first.

Still, the wrangling in the halls of Congress, in courts and at ballot boxes about how gays are treated shows no sign of abating anytime soon.

"All social justice movements are two steps forward, three steps back," said Fred Sainz, spokesman for the Human Rights Campaign, the nation's largest gay-rights group. "It's always been a lot of highs and sometimes more lows, but the highs tend to be more momentous than the lows."

Social conservatives, though disappointed with the Senate vote, disagree that there is a link between the military and marriage.

"It's a tragic day for America," said Peter Sprigg, senior fellow for policy studies at the Family Research Council. "But I don't think this will really affect the marriage issue very much. It's been rejected by voters in 31 states."

Indeed, the most important victories for gays have been won this year in the courts and Congress, rather than among the electorate.

In July, a federal judge in Massachusetts ruled that the federal Defense of Marriage Act, which defines marriage as between one man and one woman, is unconstitutional.

The Obama administration supported the statute, saying it's obligated to defend federal laws, even though President Barack Obama has called it "abhorrent."

In August, a federal judge ruled that Proposition 8, the same-sex marriage ban passed by California voters, is unconstitutional. The ruling is on hold pending appeal.

And in September, another federal judge ruled the "don't ask, don't tell" law unconstitutional in response to a lawsuit brought by the gay group Log Cabin Republicans.

"The momentum in America," said Evan Wolfson, executive director of the national advocacy organization Freedom to Marry, is "toward the freedom to marry and ending unfair treatment of gay people."

Gay marriage is legal in Massachusetts, Connecticut, Iowa, New Hampshire, Vermont and the District of Columbia.

Wolfson noted that 40 percent of Americans now live in states where some form of marriage or civil union for gay couples is recognized.

Although many in the gay community have accused Obama of being slow and inconsistent on the issue, his administration has supported a number of legislative and policy advancements on behalf of gay Americans.

Those include a hate crimes law that would allow federal prosecution of crimes where a victim is targeted because of sexual orientation or sexual identity, such as transgender.

The administration also extended certain benefits to partners of federal employees, recognized same-sex marriage certificates for the purposes of name changes on passports and gave hospital visitation protections to the same-sex partners of patients on Medicare and Medicaid, among other things.

"This is the first year in which we saw not one, but two polls showing the majority of Americans nationwide support the freedom to marry," Wolfson said. Fifteen years ago, little more than a quarter of Americans supported same-sex marriage.

Chad Griffin, president of the board of the American Foundation for Equal Rights, said he'll celebrate the likely demise of "don't ask, don't tell" — for five minutes.

"Gay and lesbian people are the last class of people in America that are actively discriminated against, overtly and directly in our state and federal laws, and a tremendous amount of progress was made in 2010 in knocking down that overt discrimination," Griffin said. "Having said that, there is a long ways to go."