Final answer:
Proposition 187 was a controversial measure in California aiming to prevent undocumented aliens from accessing public programs like schools and health clinics, but it was deemed unenforceable by federal courts due to conflict with federal immigration laws.
Step-by-step explanation:
The question asks about the features of Proposition 30 from 2012, but the information provided relates to Proposition 187 instead. Proposition 187 was a significant measure in California's history that aimed to make it illegal for undocumented aliens to receive benefits from public programs such as schools and health clinics. When Proposition 187 was approved by California voters in 1994, it created a polarizing effect politically and sparked a surge in political activism among Latino voters. However, the proposition was eventually found to be preempted by federal immigration laws and deemed unenforceable by federal courts.
Proposition 187 was controversial because it sought to deny undocumented immigrants access to public services and required proof of legal residency for children to attend public schools. It resulted in a legal challenge where a federal court ruled that regulating immigration was a federal responsibility, rendering Proposition 187 unconstitutional. This initiative's approval and subsequent legal battles exemplified the tension between state and federal powers regarding immigration policy and highlighted the polarized opinions on how to handle undocumented immigration within the United States.