In 2008, the major contenders for the Democratic presidential nomination, including Barack Obama, Joe Biden and Hillary Clinton, may have differed mightily over Iraq, health care, and diplomatic relations with our enemies -- but they stood firmly together in their opposition to same-sex marriage.
It's hard to imagine such unanimity ever occurring again in a field of Democratic presidential contenders.
"I believe the political class in Washington is behind where the American people are on this issue," Democratic strategist Steve Elmendorf told ABC News.
The political earth has been shifting in recent months on the gay marriage issue and some high-profile Democrats have been quick to follow.
Sen. Chuck Schumer, D-N.Y., a member of the Democratic leadership team in the U.S. Senate, recently announced he had dropped his opposition to same-sex marriage.
"It's time. Equality is something that has always been a hallmark of America, and no group should be deprived of it," Schumer said in a statement. "New York, which has always been at the forefront on issues of equality, is appropriately poised to take a lead on this issue."
Howard Dean, the former Democratic National Committee chairman and ex-governor of Vermont, revealed his new position on ABC News' "Top Line" this week when he said he would have signed the same-sex marriage legislation recently enacted in Vermont by the state legislature.
Dean also indicated that political positioning on this issue appears to be almost inevitably moving in the direction of support for gay marriage.
"This is changing," said Dean. "You know, gay people are seen as people first and then as gay or lesbian later. That's the way it should be. The same as African Americans. The same as Hispanics. The same as everybody who is a member of a minority group. We have to see our humanity first and then whatever category we fall into afterward."
When Gov. John Baldacci, a Democrat, signed same-sex marriage into law last week in Maine, he said, "In the past, I opposed gay marriage while supporting the idea of civil unions. I have come to believe that this is a question of fairness and of equal protection under the law, and that a civil union is not equal to civil marriage."
Polling shows the country moving with deliberate speed on the issue. According to the latest ABC News/Washington Post poll, 54 percent of moderates and 52 percent of independents now favor gay marriage. That's an uptick from 38 percent and 44 percent, respectively, in 2006.
The issue still clearly cuts along partisan lines, but with 62 percent of all Democrats in favor of gay marriage, party leaders and elected officials who once opposed gay marriage will likely seek to align themselves with the majority of the party they seek to lead.
It is no surprise that the three aforementioned Democrats who recently switched their positions on the issue hail from the Northeast. According to the ABC News/Washington Post poll, support for gay marriage peaks in the East at 59 percent and gets its lowest level of regional support in the South, where only 42 percent of voters approve of same-sex marriage.
Sen. Kirsten Gillibrand, a moderate Democrat from upstate New York who is likely to have a Democratic primary battle on her hands in New York next year, made sure her position on same-sex marriage was known -- she supports it -- as soon as Gov. David Paterson appointed her to replace Hillary Clinton in the U.S. Senate.
The action in the states does not seem poised to slow down anytime soon. The New York State Assembly just passed a same-sex marriage bill this week, though the bill's fate is uncertain in the state Senate. And in New Hampshire last week, a bill passed out of the legislature and is now on its way to Democratic Gov. John Lynch's desk.
Lynch has been opposed to same-sex marriage in the past and has not yet made his position on the current legislation known.
President Obama remains opposed to same-sex marriage. ABC News' Jake Tapper has pressed White House press secretary Robert Gibbs twice in the last two weeks on the subject to see if the president is perhaps reconsidering his position in light of the swift movement on the issue both legislatively in the states and in national public opinion.
Gibbs continued to express the president's support for civil unions, but indicated his opposition to gay marriage is unchanged.
"I think the president's position on same-sex marriage is -- has been talked about and discussed," Gibbs said in response to a question seeking reaction to Baldacci's action last week in Maine.
It is unclear if the political winds and his thinking on the issue will have changed significantly enough to cause Obama to drop his opposition to same-sex marriage by the time his 2012 re-election campaign rolls around, but some political observers don't rule it out.
"I think it's possible in 2012, but certainly in 2016, that the Democratic nominee for president will be for gay marriage," said Elmendorf, the Democratic strategist. "There is an old expression in Washington: 'Flip-flopping is OK as long as you end up on the right side with the voters.'"