Associated Press
People light candles in front of the Alabama State Capitol during a rally against Alabama's HB56 on Sunday evening, Aug. 28, 2011, in Montgomery, Ala.

You don't have to spend too much time watching a video of farmers speaking at a truck stop forum in Alabama to understand, in clear terms, the practical effects of anti-illegal immigration laws that are passed with the intent of demonizing, stereotyping and punishing people who come to this country in response to labor demands and with an eye toward helping themselves and their families.

Alabama lawmakers recently passed a law that requires businesses and schools to make sure their employees and students are in this country legally. It also provides criminal penalties for anyone who knowingly conducts business with an illegal immigrant, including harboring them or transporting them. Police have the right to ask anyone they suspect of being undocumented to provide papers. Even churches that provide charity or landlords who rent to such people would find themselves in legal trouble.

A federal judge has temporarily blocked the law from taking effect, but that hasn't kept it from having an impact. The farmers who spoke at the truck stop were clear. They have no workers to pick or load sweet potatoes, tomatoes and other crops. Every day the crops stay in the ground costs millions of dollars. Every crop that is picked but not loaded and shipped has a similar effect.

Without a crop, everyone who transports, processes and sells these items will be affected. Ultimately, consumers will pay either through shortages of certain items or through higher costs, or both. That is hardly a helpful strategy at a time of economic hardship nationwide.

If the farmers had the resources, they could raise wages to a level that might appeal to legal aliens or American citizens, but consumers still would bear the costs, and the farmers would have trouble competing against growers in other nations who still rely on inexpensive labor.

The Alabama controversy comes at a time when Utah Rep. Jason Chaffetz is pushing a bill that would require all employers in the nation to use an E-Verify system to determine whether employees are legal residents. Both the bill and the Alabama law focus solely on enforcement and punishment, rather than on recognizing and providing for the market factors that bring undocumented workers to the United States in the first place.

The nation's agricultural economy relies on inexpensive immigrant labor. Utah recently passed a law that recognizes this and allows a pathway for such workers to perform their necessary tasks while helping law enforcement better judge who is here for economic reasons and who might be here to cause trouble.

The federal government needs to step up to its responsibility for better border control. In the meantime, however, states that decide to punish and persecute people who are needed for important jobs do much more harm than good.