In its 2013 decision in Arizona v. The Inter Tribal Council of Arizona, the Supreme Court ruled 7-2 that Arizona’s proof of citizenship law for voter registration violated the 1993 National Voter Registration Act (NVRA). In 2004, Arizona voters approved Proposition 200, a stringent anti-immigration law that included provisions requiring proof of citizenship to register to vote and government-issued photo ID to cast a ballot. Last year, the US Court of Appeals for the Ninth Circuit blocked the proof of citizenship requirement, which it said violated the NVRA. Under the 1993 act, which drastically expanded voter access by allowing registration at public facilities like the DMV, those using a federal form to register to vote must affirm, under penalty of perjury, that they are US citizens. Twenty-eight million people used that federal form to register to vote in 2008. Arizona’s law, the court concluded, violated the NVRA by requiring additional documentation, such as a driver’s license, birth certificate, passport or tribal forms. According to a 2006 study by the Brennan Center for Justice, at least 7 percent of eligible voters “do not have ready access to the documents needed to prove citizenship.” The Supreme Court affirmed the lower court ruling, finding that states like Arizona could not reject applicants who registered using the NVRA form. Now Arizona and Kansas—which passed a similar proof-of-citizenship law in 2011—are arguing that the Supreme Court’s decision applies only to federal elections and that those who register using the federal form cannot vote in state and local elections. The two states have sued the Election Assistance Commission and are setting up a two-tiered system of voter registration, which could disenfranchise thousands of voters and infringe on state and federal law.