Supporters of gay marriage in Washington state declared a victory on Wednesday, saying the arithmetic was on their side.

While a final tally has yet to be released, Washington United for Marriage spokesman Zach Silk said he was confident Referendum 74 would pass, which would allow the marriage law approved by lawmakers to take effect on December 6.

With 52% of precincts reporting, the measure was narrowly leading 52% to 48%. The Olympian reported that the measure was losing in 31 out of the state's 39 counties.

“This victory is a joyous step forward for millions of gay and lesbian people in Washington and around the country who have dreamt of someday being able to marry the person they love,” Thomas Wheatley, director of organizing for Freedom to Marry and a key campaign adviser to Washington United for Marriage, said in a statement. “Washingtonians know that marriage means something important and special to all couples, their families, and their friends – including gay couples and their loved ones. Washington’s campaign mobilized unprecedented support from businesses, faith leaders, and young voters, demonstrating that the freedom to marry matters to all people and setting a powerful example as we continue to work to win marriage nationwide.”

Voters in Maryland also decided to uphold a similar law on Tuesday, and Maine became the first state to ever approve marriage equality at the ballot box.

Minnesotans rejected a proposed constitutional amendment which would have defined marriage as a heterosexual union.

In Washington, the legislation was approved first in the Senate, where several Republican senators spoke up in support of marriage equality.

“This has been a very personal and emotional issue for everyone,” Senator Steve Litzow told colleagues. “I'm voting for this bill because I believe it's the right thing to do. I believe an adult should have the right to marry the person they love. It's that simple for me. It's about the personal freedom of two consenting adults to make that choice for themselves.”

A week later, a majority in the House agreed after a two-hour debate. Among those voting for passage was Republican Rep. Maureen Walsh, who said she was voting in favor because her lesbian daughter is “a fabulous human being” for whom she someday wants to throw a wedding. She later appeared in an ad for Washington United for All Families, the group working to approve Referendum 74.

Governor Chris Gregoire, a Democrat, signed the measure into law.

In 2007, Washington began recognizing gay couples with domestic partnerships. A 2009 expansion of the law – dubbed “everything but marriage” – gave gay couples all the protections of marriage. Opponents failed in an effort to roll back the legislation at the ballot box.