Sen. Mary Margaret Haugen
Sen. Mary Margaret Haugen was the 25th lawmaker to promise to vote in favor of same-sex marriage, poising Washington state to pass the measure. Washington Senate

On Monday, Washington Sen. Mary Margaret Haugen announced she would vote in favor of gay marriage, poising the state to become the seventh in the nation to allow same-sex couples to marry.

Haugen, a Democrat from Camano Island, said in a statement she went from undecided to in favor of gay marriage because it's an issue about respecting others. She added that a recently introduced amendment that would give churches the right to choose whether or not to marry a couple swayed her decision.

Years ago I took exception to my parents' beliefs on certain social issues, and today my children take exception to some of mine. Times change, even if it makes us uncomfortable, Haugen said in the statement. I think we should all be uncomfortable sometimes. None of us knows everything, and it's important to have our beliefs questioned. Only one being in this world is omniscient, and it's not me.

Haugen's choice makes her the 25th senator to promise to vote in favor of gay marriage and the 25th vote needed to get the measure passed (the Washington Senate has 49 members).

The bill was publically endorsed earlier this month by Gov. Christine Gregoire, a Democrat. Although it had wide support in the House, it had been a few votes short in the Senate, according to The New York Times.

Seattlepi.com reported that Haugen is up for re-election in a Republican-leaning district.

For some people, this is a simple issue, Haugen said. I envy them. It has not been easy for me.

No date is set for the gay marriage vote in Washington's legislature, but if it is passed in this legislative season, gay couples can begin marrying in June, according to The Associated Press.

Sen. Ed Murray, a gay Seattle lawmaker who led the push for gay civil rights and domestic partnership in Washington, said he felt humbled when hearing the 25th vote had been secured, according to The Associated Press.

It's an emotional moment, he said. I want to smile and cry at the same time.

The National Organization for Marriage vowed to campaign for a referendum. According to The Associated Press, they plan on spending $250,000 to help fund candidates challenging Washington Republicans who cross party lines and vote in favor of same-sex marriage.

NOM will not stand by and let activist politicians redefine marriage, the bedrock of civilization, without voters having a say, said the organization's president in a statement.

If Washington passes the measure, it would be joining New York, Vermont, Massachusetts, New Hampshire, Connecticut and Iowa in allowing same-sex marriage.