This paper argues that the Immigration Reform and Control Act of 1986 is a composite of contradictory measures. On one hand, employer sanctions are meant to curtail the employment of undocumented workers and preserve the U.S. labor market for legal residents and citizens; on the other hand, special foreign worker programs are designed to enhance the supply of immigrant workers. In an effort to make sense of these contradictions, the author places the legislation in historical context and proposes a dialectical model of immigration policymaking.