Passed by a wide margin of California voters in 1994, Prop. 187 is primarily remembered as a law that tried to deny state-funded health care and education to unauthorized immigrants. Far less attention has been paid to Section Four in Prop. 187 that required all law enforcement agencies (LEAs) in California to “fully cooperate” with federal immigration authorities. Specifically, these provisions required LEAs to verify the legal status of any arrestee “suspected” of being in the U.S. unlawfully, notify the arrestee of his/her unlawful status, and report the arrestee to state and federal immigration authorities.

Though never enforced, Section Four played an extremely important role in introducing the concept of LEA enforcement into our immigration policy debates. Prior to the passage of Section Four, the idea that LEAs should be involved in immigration enforcement on a regularized and mandatory basis simply did not exist. The intense publicity around Prop. 187 and subsequent efforts to enact Prop. 187-type laws in other states nationalized the immigration enforcement debate. At the federal level, the result was the creation of the voluntary 287(g) program and the passage of a federal “anti-sanctuary” law. At the state level, states enacted laws that mirrored the mandatory nature of Prop. 187 more closely, requiring LEAs within the states to check the immigration status of people arrested for other offenses. This article explores the influence of Section Four on LEA enforcement of immigration laws.