1994 California Proposition 187

California Proposition 187 (also known as the Save Our State (SOS) initiative) was a 1994 ballot initiative to establish a state-run citizenship screening system and prohibit undocumented immigrants from using non-emergency health care, public education, and other services in the State of California. Voters enacted the proposed law at a referendum on November 8, 1994. The law was challenged in a legal suit the day after its passage, with almost all provisions found unconstitutional by a federal district court on November 11. In July 1999, Governor Gray Davis halted state appeals of this ruling, effectively killing the law.

The enactment of Proposition 187 reflected state residents' concerns about illegal immigration to the United States. Opponents cited the specter of "totalitarianism", finding the initiative unfairly targeted "children and would turn tens of thousands of adults into government informants", while being motivated by bigotry against people of Hispanic or Asian origin; supporters maintained that their concerns were economic: that the state could not afford to provide social services for so many people who had entered the country undocumented or overstayed their visas. The California Legislative Analyst's Office later said that the cost of verification would be greater than any fiscal benefits of the ballot measure. As the state's demographics have shifted to include more immigrants, the reversal of Proposition 187 has been cited as a reason for the decline of the California Republican Party.