Most media outlets are trumpeting the decision by the Supreme Court to strike down the state of Arizona's requirement that proof of citizenship be supplied when registering to vote as a "victory" for those who believe it a burden to prove your right to vote.

But, the Supreme Court had a few surprises in the guts of the decision that gives hope to states who want to pass voter registration laws that have common sense requirements to prove citizenship.

SCOTUS Blog's Lyle Denniston:

For those who would look to Congress to keep open, and expand, the right to vote for the presidency and for members of Congress, Justice Antonin Scalia's opinion for a majority (seven to two on several points, six to three on one other very key point) promised that Congress could pass its own laws on the voter registration process, and states would have to yield to those.   In this case, a federal voter registration form only requires would-be voters to declare that they are citizens, but Arizona would also require them to show hard proof that they are.   On that point, apparently, Arizona must yield to the federal form, and sign up those who present it.

The part of the Scalia opinion that went the furthest in Congress's favor -- and on which the majority was only six to three, because Justice Anthony M. Kennedy would not join on this point -- laid down a seemingly very broad rule on when state election law requirements must yield to those enacted by Congress.

There is a customary rule that courts are to operate on the basic premise that, when Congress and the states act in the same field, state laws won't be displaced unless Congress explicitly says they must yield.  That "presumption against preemption," in technical terms, does not even apply to the joint enterprise of Congress and the states in regulating elections, according to the new decision.   Thus, in this one field, states do not get the benefit of the doubt when they pass election laws that appear to be, or are, different from what Congress has mandated.

If a reader of the Scalia opinion stopped at the top of page 13, the impression would be very clear that Congress had won hands down in the field of regulating federal elections.   But from that point on, there is abundant encouragement for what is essentially a states' rights argument: that is, that the states have very wide authority to define who gets to vote, in both state and federal elections.

Denniston notes the bottom line: "[S]tates cannot now require voters to show proof that they are U.S. citizens, but the Court has given them a plan that could gain them that power."

The one constitutional tradition that appears fairly safe with this court is the states' ability to run their own elections as they see fit, unless Congress is very specific in their intrusion. This doesn't guarantee that this will continue. A liberal congress could overwrite just about any state election law they wanted to. But as it stands now, states like Arizona who want to insure that only American citizens are allowed to vote, have an opprotunity to do so as long as the legislation they write conforms to Supreme Court guidelines.

Not quite the total "victory" we are led to believe by most media reports on the decision.