The U.S. Department of Justice is suing Arizona over a new law requiring people who use a federal form to register to vote to provide additional proof of citizenship if they want to vote for president.
The lawsuit filed on Tuesday says the law signed by Republican Gov. Doug Ducey in March is in direct conflict with a 1993 federal voter registration law and also violates the Civil Rights Act of 1964.
The law adds requirements for the federal form that were directly rejected by the U.S. Supreme Court in a 2013 Arizona case.
The Republican-controlled Legislature was well aware of the federal law and the Supreme Court decision written by the late conservative icon Justice Antonin Scalia but went ahead anyway.
Two other legal challenges have also been filed.