"The connection between farm labor and immigration policies is a longstanding one, particularly with regard to U.S. employers' use of workers from Mexico. The Congress is revisiting the issue as it debates a broad-based guest worker program, increased border enforcement, and employer sanctions to curb the flow of unauthorized workers into the United States. Two decades ago, the Congress passed the Immigration Reform and Control Act (IRCA, P.L. 99-603) to reduce illegal entry into the United States by imposing sanctions on employers who knowingly hire individuals who lack permission to work in the country. In addition to a general legalization program, IRCA included legalization programs specific to the agricultural industry that were intended to compensate for the act's expected impact on the farm labor supply and encourage the development of a legal crop workforce. These provisions of the act, however, have not operated in the offsetting manner that was intended: substantial numbers of unauthorized aliens have continued to join legal farm workers in performing seasonal agricultural services (SAS). A little more than one-half of the SAS workforce is not authorized to hold U.S. jobs. Perishable crop growers contend that their sizable presence implies a shortage of native-born workers willing to undertake seasonal farm jobs. Grower advocates argue that farmers would rather not employ unauthorized workers because doing so puts them at risk of incurring penalties. Farm worker advocates counter that crop growers prefer unauthorized workers because they are in a weak bargaining position with regard to wages and working conditions."
CRS Report for Congress, RL30395
National Agricultural Law Center http://www.nationalaglawcenter.org/crs/