Debate over farm subsidies

Economist Benjamin Powell, who was part of our BB&T Free Market Process Speaker Series last November, was recently on MSNBC discussing U.S. farm subsidies.  What is interesting is that the advocate for farm subsidies argues that to create stability in food prices and supplies we need to ensure that a country produces food within its own borders and not allow for free trade of agricultural products.  Perhaps I missed the memo, but why are agricultural product different from cars, clothing, or DVDs?  How can purchasing cotton or other products from Afghanistan or other parts of the world harm the U.S. economy.  These farm subsidies like tariffs, or bailouts are just another means of protecting a particular industry at the expense of all consumers.

What I want to understand is why is it than when government officials intervene in the market they argue that this particular market is some how unique.  The financial markets, farming, the auto industry, healthcare these are all some how industries or markets that are different from clothing, toys, or electronics?  As I understand it these markets are still subject to the laws of supply and demand.

Here is the video.