By Keith B. Richburg
Washington Post Staff Writer
Tuesday, April 7, 2009; 2:23 PM

NEW YORK, April 7 -- Vermont on Tuesday became the fourth state to recognize gay marriage, and the D.C. Council voted to recognize same-sex unions performed in other states. The two actions give same-sex marriage proponents new momentum, following a similar victory last week in Iowa's Supreme Court.

"I think we're going to look back at this week as a moment when our entire country turned a corner," said Jennifer C. Pizer, the national marriage project director for the advocacy group Lambda Legal. "Each time there's an important step forward, it makes it easier for others to follow."

The issue is also advancing in New Hampshire, where it has passed the state House and is awaiting action by the Senate, as well as in Maine and New Jersey, which are debating same-sex marriage legislation.

New Jersey, which now allows civil unions for gay couples, is a particular prize for advocates because of its large size, and they are hoping for action this year after a commission in December recommended making marriage laws gender-neutral. Gov. Jon S. Corzine has said he would sign a same-sex marriage bill.

New York recognizes same-sex marriages performed in other states, and Gov. David Paterson has said he supports full marriage rights for same-sex couples. And sometime before early June, the California Supreme Court must decide whether Proposition 8, which banned gay marriage in the Golden State about five months after it became legal, was a valid use of the referendum power.

The action Tuesday in Vermont came swiftly, surprising even some of the proponents of gay marriage who were still celebrating their victory last Friday, when the Iowa Supreme Court ruled that same-sex marriages could go ahead.

The two houses of Vermont's legislature voted last week for a same-sex marriage bill -- four votes short of a veto-overriding majority -- and Gov. Jim Douglas (R) vetoed it Monday. But Tuesday, several house members who voted against it last week switched sides to support the override, making gay marriage law.

The final vote was 100 to 49 to override the governor's veto. The initial vote last week was 94 to 52. Vermont has no mechanism for a citizen referendum to override the law.

"All of us are thrilled at the pace," said Jennifer Chrisler, executive director of the Massachusetts-based Family Equality Council, which advocates for gay rights. "This is a great day."

With the Vermont vote, and the D.C. Council action, Chrisler said, "I think this is a very significant indicator of how the tide is turning in this country and folks recognize that this is about love and commitment." She added, "The arc of history is long but bends towards justice."

The Vermont vote Tuesday was particularly symbolic for activists because this is the state that nine years ago became the first to legalize civil unions between same-sex couples. Seen at the time as revolutionary, Vermont has in recent years seen other states surpass it by legalizing same-sex marriage outright.

"Vermont opened an important back door," Pizer said. "Now it has invited gay people to enter through the front door of marriage."

Some 43 U.S. states have laws prohibiting gay marriages -- 29 of those with constitutional amendments specifically defining marriage as between a man and a woman -- but many of those are being subjected to court challenge. Gay activists also hope to challenge the 1996 federal "Defense of Marriage Act" that defines marriage as between a man and a woman.

Domestic partnerships already are legal in the nation's capital, and gay couples married in other states are recognized as domestic partners when they move the city.

Tuesday's legislation in Washington was billed as an important milestone in gay rights, because it explicitly recognizes married couples from other states.

The initial council vote was 12-0. The unanimous vote sets the stage for future debate on legalizing same-sex marriage in the District -- and a clash with Congress, which approves the city's laws under Home Rule. The council is expected to take a final vote on the legislation next month.