Among other things, [the Farm Bill] determines which crops will be subsidized and which will not, and in the case of the carrot and the Twinkie, the farm bill as currently written offers a lot more support to the cake than to the root. Like most processed foods, the Twinkie is basically a clever arrangement of carbohydrates and fats teased out of corn, soybeans and wheat—three of the five commodity crops that the farm bill supports, to the tune of some $25 billion a year. (Rice and cotton are the others.) For the last several decades... U.S. agricultural policy has been designed in such a way as to promote the overproduction of these five commodities, especially corn and soy.
Agriculture also persists as the millstone around the neck of international trade negotiations, grinding the process to a halt. Promises have not been kept to end unfair practices that harm farmers in the developing world, such as the dumping of surplus goods. Environmental pressures are also bearing down on the situation. Policy Innovations recently covered the use of food crops to produce ethanol—the result is a complex economy of tariffs, Brazilian sugar, American corn, and rising tortilla prices in Mexico.
The Minnesota-based Institute for Agriculture and Trade Policy has been covering all these topics at its AgObservatory site, with a special section dedicated to the Farm Bill.