Thursday's 5-4 decision by the U.S. Supreme Court may cast doubt on criminal sentences in as many as a dozen states, but it corrects an injustice that violates a fundamental precept of our Constitutional system - the right to a trial by jury.

The decision bitterly split the court, but interestingly, united its most conservative and most liberal members into a majority. The decision involved a criminal case from Washington state in which a man pleaded guilty to kidnapping his ex-wife. Under Washington law, that crime ordinarily carries a maximum sentence of 53 months. But the judge added 37 months to the sentence, based on a state sentencing guideline that allowed him to find that the defendant, Robert Blakely, acted with "deliberate cruelty."

The court overturned the sentence because Blakely didn't admit to the "deliberate cruelty," and no jury determined that he acted in such a way. Writing for the majority, Justice Antonin Scalia said it is an established principle of law that a judge's authority to sentence "derives wholly from the jury's verdict."

Scalia, one of the court's most conservative members, was joined in the decision by another conservative, Clarence Thomas, as well as Justices Ruth Bader Ginsburg, John Paul Stevens and David H. Souter, who are usually considered the court's more liberal members.

Several states, including Ohio, use sentencing guideline systems similar to Washington's. Justice Sandra Day O'Connor, writing a dissent, worried that "tens of thousands of criminal judgments are in jeopardy" because of the decision. That may be an exaggeration, but the numbers should not be allowed to overshadow the principle.

The Sixth Amendment to the Constitution guarantees criminal defendants the right to trial by jury. If states want to use such things as "deliberate cruelty" to increase sentences, they have the right to hold separate sentencing trials before the jury, to present such evidence, as Ohio now does in death penalty cases.

But if a defendant pleads guilty to a crime with a specific sentence, he has a right to expect that sentence, not one with extra time added on at the discretion of "a lone employee of the state," as Scalia wrote.