2004 Arizona Proposition 200

Proposition 200, the "Arizona Taxpayer and Citizen Protection Act", was an Arizona state initiative passed in 2004 that basically requires: (a) persons to provide proof of citizenship to register to vote; (b) voters to present a photo identification before receiving a ballot at the polling place; and (c) state and local agencies to verify the identity and eligibility, based on immigration status, of applicants for non-federally mandated public benefits. The proposition also makes it a misdemeanor for public officials to fail to report violations of U.S. immigration law by applicants for those public benefits and permits private lawsuits by any resident to enforce its provisions related to public benefits. The requirement to provide proof of citizenship to register to vote was later ruled invalid in federal court.

Authors of the ballot measure, the "Protect Arizona Now" committee, claimed that the provision of state identification and public benefits to individuals without adequately verifying their immigration status gave rise to opportunities for voter fraud and imposed economic hardship on the state.

Opponents of the ballot measure asserted that it was anti-immigrant and reminiscent of California's 1994 Proposition 187, as well as disputed the existence of voter fraud and argued that immigrants were important contributors to the state's economy.