One thing I have learned is that the law is extremely nuanced and Supreme Court decisions are very specific to the argument in front of them.  In 1993 the federal government provided the voter application form which requires that the applicant swear they satisfy the citizenship requirement.  I suppose the belief is that the laws against voter fraud would keep someone from falsely swearing they are eligible to vote.  The issue before the court was that the state of Arizona further required the applicant to provide proof of citizenship in order to complete the application.  The Supreme Court ruled that Arizona could not do this, affirming the argument that the state must yield to federal law in this matter.

It was a confusing decision, and at first glance appeared to subvert the state of Arizona’s right to ask for proof of citizenship, which added an additional requirement to completing the federal voting application.  But when the laws conflict federal law trumps state law.  The best commentary and explanation in plain English I found was from Lyle Denniston, SCOTUS Blog reporter, who after reading the decision and dissenting opinions, writes:

“On the one hand, the Supreme Court agreed that, for now, Arizona’s proof requirement must yield to the federal form’s approach — that is, it is enough to register, using that form, if the would-be voter swears that he satisfies the citizenship requirement.

On the other hand, however, the Court also ruled that Arizona can seek permission from federal officials to impose its proof-of-citizenship requirement.  If it fails with that request, it can go to court and argue that it has a constitutional right to make proof of citizenship a binding requirement for all voters.”

I hope Arizona pursues this argument, as a positive decision would benefit every state in the future.