At first glance, the U.S. Supreme Court’s decision regarding an Arizona law requiring voters to give proof of citizenship when registering to vote is a victory for those pushing for increased voter access. And for now, anyway, it is. But the decision is rooted in something a bit more arcane and procedural than an open-arms ideology.

The court considered whether an Arizona ballot initiative passed in 2004 requiring that all who registered to vote in the state prove their U.S. citizenship. That requirement applied whether the voter used the state registration form or the federal one. The former had a citizenship requirement while the latter, governed by the 1993 National Voter Registration Act, does not. In its 7-2 opinion, the court reminded Arizona that, for federal elections, it must adhere to the federal rules, which do not require proof of citizenship for registration.

State elections, though, are another matter, and the court’s decision does not preclude registration for Arizona-only votes from requiring proof of citizenship. That is one hint at the decision’s procedural – rather than philosophical – focus.

The ruling goes further, though, in that it opens the door for a change on the federal registration form. Because the current version of it does not require proof of citizenship, the opinion – written by Justice Antonin Scalia – says Arizona outgrew its britches and trampled on federal law with a more restrictive law of its own.

However, the decision invites Arizona to request a revised version of the federal form that requires citizenship proof. To do so, Arizona would have to plead its case to the Election Assistance Commission, a federal body composed of presidential appointments. On paper, this is an easily arranged next step that may or may not produce Arizona’s intended result, but at least could settle the matter – if the commission had any members. Currently, it does not.

This all serves to illustrate the salient points of Monday’s ruling: that Arizona’s citizenship requirement is not unconstitutional in and of itself, but the state’s attempt to supersede existing federal rules governing federal elections is too much. Should those rules change – and the opinion suggests that, in theory at least, they can do so relatively easily – Arizona then would be free to require proof of citizenship of all its voters.

That is an important distinction to consider when evaluating the court’s decision. While the ruling is a victory for those seeking to do away with restrictive laws that limit voter access – particularly among minorities, and individuals of lesser economic or physical means – it is far from an intractable guarantee that laws such as Arizona’s are inappropriate.

The court has ruled on a procedural notion that has very real practical implications for voters; it has not said what it thinks about states’ attempts to limit the ease with which voters can weigh in on elections. That is a far bigger question that will take more than a trip to the Election Assistance Commission to settle.