Final answer:
Proposition 187, a ballot initiative in California, aimed to make it illegal for undocumented aliens to receive public benefits. However, it was deemed unenforceable by federal courts. The law would have led to political divisions and increased activism among Latino voters.
Step-by-step explanation:
O'Sullivan's article about California likely refers to the proposition mentioned in the provided information, Proposition 187. This controversial ballot initiative, approved by California voters, aimed to make it illegal for undocumented aliens to receive public benefits such as education in schools and health services. However, a federal court determined that the measure was preempted by federal laws on immigration. The article suggests that the law would have polarized California politics along ethnic and party divisions and led to increased political activism among Latino voters.