Chief Justice John Roberts came to the U.S. Supreme Court with a mission. He wanted the court to begin deciding cases on the narrowest possible terms and, if possible, with less of a cacophony of squalling voices and intricately nuanced opinions.

The Roberts principle was on full display in the Voting Rights Act decision, written by Roberts himself, the court issued on Monday.

A small utility district in Texas had sued to get out from under the preclearance requirements of the Voting Rights Act. Under the act, the political jurisdictions of some states, including Texas and Arizona, have to submit all changes in election laws and procedures to the federal government for approval before implementing them.

The utility district was formed in 1987 and had no history of discriminatory election practices. There is a provision for political jurisdictions to get out from the preclearance requirement but the district was told that, since it wasn't involved in voter registration, it was ineligible.

So, the district sued, asking the court to declare either that it was eligible to be exempted or that preclearance unconstitutionally subjected equally sovereign states to different federal treatment.

In his opinion, Roberts wrote that preclearance was, indeed, constitutionally troubling. However, he also found that the district was eligible for an exemption, and that the case could be decided on that narrow basis, so he didn't opine on preclearance's constitutionality.

Seven other justices signed onto the Roberts opinion without offering independent views, a rarity. Only Justice Clarence Thomas wrote separately, to say that he agreed that the district was eligible for an exemption, but that the court should also go ahead and say that preclearance was unconstitutional.

The Roberts principle is intended to keep the court constrained and provide greater clarity and guidance to future litigants by forging greater consensus. But when an important constitutional question is squarely before the court, as it was in this case, ducking it disserves the body politic and unfairly burdens litigants.

The Voting Rights Act, when initially enacted in 1965, forbade certain practices that had been used to prevent blacks from voting, such as literacy tests and poll taxes. The preclearance requirement was intended to prevent Jim Crow states from evading these prohibitions or devising new barriers. Preclearance was originally scheduled to expire after five years, but kept getting extended.

When the Voting Rights Act was renewed in 2006, preclearance was extended for another 25 years, until 2031. So, the election procedures for some states will have been subjected to far more extensive federal oversight than others for 66 years.

In the meantime, the differences between the states in terms of minority voter registration and voting have become statistically insignificant.

Because the court ducked the constitutionality of preclearance, the Texas utility district now has to make its case to be exempted, an arduous legal undertaking. And if it fails, it then has to go back to court to ask that preclearance be declared unconstitutional.

Moreover, the language of the Roberts decision about the suspect constitutionality of continuing the preclearance requirement is practically an invitation to litigate just that issue.

Arizona should accept that invitation. Arizona's entrapment in preclearance is positively Kafkaesque.

Arizona is subject to preclearance because in 1972 voter turnout was low and bilingual ballots weren't used. But the federal government didn't require bilingual ballots until the Voting Rights Act was amended in 1975. In other words, Arizona is subject to preclearance because it didn't comply with a federal requirement before it existed.

But no one - not the utility district, not Arizona, nor any other political jurisdiction subject to preclearance - should have to relitigate the issue.

The constitutionality of preclearance was squarely before the court. It was fully briefed and argued. It's an important issue affecting 16 states and some 12,000 political subdivisions.

The court shouldn't have ducked it.