Until the biotech giants tromped into the campaign, Measure 27 on the November ballot looked simple. This well-intentioned but impractical proposal would require that all genetically engineered foods sold in or distributed from Oregon be labelled as such - not a bad idea at the national level, but potentially troublesome for a single state. The lavishly funded campaign against Measure 27 has created a powerful temptation to vote yes - but not quite powerful enough. Oregonians should follow their heads, not their hearts, and reluctantly vote no. Monsanto, DuPont and other producers of genetically engineered agricultural products have raised $4.6...