The people of Missouri have voted to ban same-sex marriage in a referendum.
The Missouri vote may set the tone for others across the US
Early results suggested 72% of voters backed a constitutional amendment banning gay marriage - making Missouri the first American state to do so.
Tuesday's poll could set the tone for similar votes taking place in up to 12 other US states this year.
Last month President George W Bush failed to win Senate support for a change to the US constitution to ban gay marriages.
Last year the state of Massachusetts legalised same-sex marriage after its highest court ruled that gay couples could be legally wed.
Although Missouri is one of 38 states which have laws defining
marriage as only between a man and a woman, some of those opposed to gay unions believe a constitutional amendment is the only way to prevent a repeat of the Massachusetts ruling in their state.
"I'm very gratified and encouraged and thankful that the
people of this state understand our current policy's a wise
public policy and they want to see it protected from a
legal challenge," said Vicky Hartzler of
the Coalition to Protect Marriage in Missouri.
Gay activists admitted they always faced an uphill battle in conservative Missouri, but hoped the experience would inform their upcoming campaigns in Louisiana, Arkansas, Georgia, Kentucky, Mississippi,
Montana, Oklahoma, Oregon and Utah, and for possible votes in Michigan, North Dakota
"We're already reaching out to these other states,
sharing with them what we learned, what worked, what didn't work, and we'll move on," said Doug Gray, campaign manager
for the Constitution Defense League.
"Ultimately we're right and they're simply wrong."
Following his setback in the Senate, President Bush says he will carry on trying to make homosexual marriages illegal nationwide.
The issue has become one of the hot topics in an election year.
The president says liberal judges and activists are trying to redefine one of the fundamental cornerstones of American society - marriage as a union between a man and a woman.
His challenger, Democrat John Kerry, the senator for Massachusetts, has said he opposes gay marriage, but supports legal recognition for homosexual couples.