Despite losing in liberal Oregon, advocates of GMO labeling say they've just begun to fight

Not even Oregon's backyard chicken owners and vegan foodies had enough money and clout to persuade voters to require labeling of genetically modified foods.

Oregon is the fourth Western state where a GMO labeling measure has failed. A similar proposal also failed Tuesday in Colorado. Those two join Washington and California, which had earlier rejected labeling by a margin of about 2 percentage points.

But GMO opponents aren't giving up. They say their "social movement" is ready to continue the fight in legislatures, on ballots, and at the federal level.

Oregonians rejected the measure by about 1 percentage point. Voters in cities like Portland supported labeling, but rural voters overwhelmingly opposed it.

Opponents of the measure raised about $20 million in Oregon, while labeling proponents brought in $7.5 million.