The Supreme Court ruled  Monday that states do not have the authority to demand proof of citizenship before accepting federal voting registration forms.
The 7-2 decision came after justices considered the legality of Arizona's Proposition 200, a 2004 law that requires an Arizona driver's license, U.S. birth certificate or other proof of citizenship before the state will accept a federal registration application form, something the justices say interferes with federal law.
The National Voter Registration Act of 1993, also known as the "Motor Voter" Act, asked states to offer voter registration when residents applied for a driver's license, social assistance or "agency based" needs such as food stamps and disability services. It also requires states to allow perspective voters to register through the mail, swearing under penalty of perjury that they are citizens, thereby not requiring identification or proof.
Taking this act into consideration, Justice Antonin Scalia announced from the bench that federal law "forbids states to demand that an applicant submit additional information beyond that required by the federal form," USA Today reported .
In addition to Arizona, this court decision may affect multiple states across the nation. According to USA Today, four other states -- Alabama, Georgia, Kansas and Tennessee -- also require proof of citizenship before voter registration, and about 30 states impose voter identification requirements at the polls.
Arizona officials have argued they should be able to pass laws like Proposition 200 to thwart immigrants in the U.S. illegally and other non-citizens from voting in U.S. elections while opponents say they attack vulnerable voting groups like minorities and the elderly.