Its gets a lot of infrastructure on ground ready for cellulosic ethanol (half of it in fact) and all that will then be needed are biodigesting vats to turn the cellulose into simple sugars for fermentation. The US has a problem with liquid fuel dependency first and foremost. Ethanol can be used to fuel air traffic. No massive change required to convert existing gasoline engines to ethanol.
Inflating food prices is also a leathal weapon in managing the US's largest threats - China and Russia where food costs take a lot of disposable income out of the equation.
Subsidising ethanol is also hyperinflating grain prices and driving massive export earnings for the US. Its about the only thing China can't do for 1/10th of the cost of the US.
There are a lot of benefits in establishing a domestic biofuel industry when you have been a major surplus producer of food and that food was selling too cheaply to export markets.
