In September, ethanol giant VeraSun Energy opened a refinery on the outskirts of this eastern Iowa community. Among the largest biofuels facilities in the country, the Dyersville plant could process 39 million bushels of corn and produce 110 million gallons of ethanol annually. VeraSun boasted the plant could run 24 hours a day, seven days a week to meet the demand for home-grown energy. But the only thing happening 24-7 at the Dyersville plant these days is nothing at all. Its doors are shut and corn deliveries are turned away. Touring the facility recently, I saw dozens of rail cars...