Gay marriage battle goes before voters in Washington state A referendum that could overturn same-sex marriage in the state of Washington has qualified for the ballot, the secretary of state's office announced Tuesday. Supporters turned in 247,331 signatures, more than double the minimum of 120,577 valid voter signatures required. A 3 percent random sample was done and of the 7,561 signatures that were sampled during the check, 6,877 were accepted. The referendum's backers are seeking to overturn a measure allowing same-sex marriage in the state, which was passed by the Legislature earlier this year. That law was supposed to take effect last Thursday, but was put on hold once the signatures were turned in last Wednesday. Gay marriage supporters have been raising money to protect the law. Zach Silk, campaign manager for Washington United for Marriage, has said he expects both sides to raise millions of dollars. Obama who? Gay marriage foes seek to extend gains Six states and the District of Columbia allow same-sex marriage, while 31 states have constitutional amendments that effectively ban gay marriage (this tally does not include California where such an amendment is under a legal challenge). A number of cases involving gay marriage are also winding through federal courts. Federal judges in Massachusetts, New York and California have in recent weeks declared the Defense of Marriage Act, or DOMA, the federal law that defines marriage as the legal union of one man and one woman, unconstitutional. President Barack Obama declared his support for gay marriage in May. Fifty percent of Americans think same-sex marriage should be legal and bestow the same rights as traditional marriage, compared to 48 percent who don't, according to a Gallup poll released last month. Opponents of same-sex marriage discount national polls, noting that whenever same-sex marriage is put before voters, it is rejected. Last month, North Carolina voters approved a constitutional amendment banning gay marriage by more than 20 percentage points. Washington state has had domestic partnership laws since 2007 and in 2009 passed an "everything but marriage" expansion of that law, which was ultimately upheld by voters after a referendum challenge. KING5 and The Associated Press contributed to this report.