In United States v. Booker (2005), the Supreme Court held that the Sixth Amendment prohibits a judge from sentencing a convicted defendant to a prison term exceeding the law’s maximum penalty for the crime committed, unless additional aggravating facts are found by the jury (or admitted by the defendant). The Court also held that all sentences must be reasonable.

In a subsequent case, Justice Scalia issued a concurrence in which he expressed concern about situations in which judges issue sentences below the statutory maximum, but which would only be reasonable in light of additional facts found solely by the judge. He proposed an “as-applied” doctrine, in which the reviewing court asks whether the sentence would be reasonable as applied to only those facts that were found by the jury.

The situation that Justice Scalia feared has now become manifest for three criminal defendants who were all convicted of selling small quantities of drugs but acquitted of conspiracy charges relating to the distribution of much larger quantities. Despite the acquittals, all three defendants received sentences four times greater than any other defendant convicted of the same crimes in the post-Booker era using the guidelines issued by the U.S. Sentencing Commission.

The defendants argue—and no prosecutor or judge has disputed—that their sentences would not be deemed reasonable without consideration of the additional evidence of conspiracy. In reviewing the sentences, the U.S. Court of Appeals for the D.C. Circuit adhered to settled precedent and declined to adopt the as-applied doctrine, and so the defendants seek to further appeal their sentences to the Supreme Court and finally resolve the question, under the Sixth Amendment, of whether a judge can base a sentence on facts that the jury did not find beyond a reasonable doubt.

In an amicus brief supporting that petition, the Cato Institute, joined by the Rutherford Institute, argues that the Sixth Amendment prohibits the increased sentencing of defendants based solely on judge-found facts of the crime, regardless of whether the final sentence remains below the statutory maximum. The defendants’ constitutional right to a jury trial can be traced back to Article 39 of the Magna Carta, which is also the historical origin of the Constitution’s prohibition on ex post facto, or retrospective, criminal laws.

Article 39 reflected a deep concern that the government would undermine the jury’s role and imprison defendants without the input of their peers. Given the status of sentencing guidelines as “law” for purposes of the Ex Post Facto Clause, the Sixth Amendment should extend to the defendant’s right to the “lawful judgment of his peers,” meaning that a judge can only render a sentence based on the jury’s factual findings.

In other words, if it’s unconstitutional to sentence a defendant based on rules issued after he commits the purported crime, it must be unconstitutional to sentence a defendant without the input of his peers.

The Supreme Court will decide whether to take the case of Jones v. United States when it comes back from its summer recess.