Ask a random person on the street how many people make up a jury and you are all but certain to hear the answer “twelve.” Going back some eight hundred years, leading English and American jurists would have answered the same. But in 1970, in a case called Williams v. Florida, the Supreme Court departed from this multi-century consensus to hold that juries as small as six people are constitutionally permissible under the Sixth Amendment. Yesterday, during the Supreme Court’s annual long conference, one of the many cases it considered whether to hear was a case called Khorrami v. Arizona that would allow it to correct this grave error. Soon we’ll know what it decided.

If the Court hears this case this term, it will have the chance to continue the work of restoring the original meaning of the Sixth Amendment that it started two years ago in a case called Ramos v. Louisiana. In that case, the Supreme Court overruled its own precedent to hold that the Sixth Amendment guarantees criminal defendants the right to a unanimous jury verdict. The Court came to that conclusion based on hundreds of years of history: the common law, state practices at the Founding era, and leading opinions and treatises from the period of ratification all confirmed that a conviction by a jury requires a unanimous decision. In so holding, the Court overruled a 1972 decision, Apodaca v. Oregon, which permitted states to convict criminal defendants on the basis of non-unanimous jury verdicts, a decision premised on the view that the unanimity requirement did not serve an important function. The Ramos Court critiqued Apodaca for “subject[ing] the ancient guarantee of a unanimous jury verdict to its own functionalist assessment,” an analysis that was also deeply flawed on its own terms.

Now, we wait to see whether the Court has taken the opportunity Khorrami presents to ensure that the Sixth Amendment’s requirements with regard to jury size also align with what constitutional text and history require.  As CAC pointed out in our brief in support of cert, the very same history the Court relied on in Ramos confirms that the term “jury” means a jury of twelve people. The jury right has its foundation in English common law, which recognized the jury as critical to the preservation of liberty. And at common law, an individual could only be convicted in a criminal trial by the unanimous consent of twelve of his neighbors and equals. As debates and commentary from the time of the Sixth Amendment’s drafting and ratification confirm, when the Framers included a right to a “jury” trial in the Constitution, they meant the right to a jury composed of at least twelve people. And the twelve-person requirement was repeatedly recognized by the Supreme Court, state supreme courts, and influential legal thinkers throughout the nineteenth and early twentieth centuries.

In Williams, the Court improperly dismissed all of this history based on a quirk in the drafting history. Provisions spelling out some of the common-law features of the jury, such as unanimity, were omitted from the final draft, and the Williams Court concluded that this meant the Framers did not mean to include the essential features of the jury at common law in the Constitution. But the Supreme Court expressly rejected that reasoning in Ramos, pointing out that it would leave the jury right “devoid of meaning.” Plus, these deletions “just as easily support” the inference that the Framers viewed such language as unnecessary in light of the well-understood meaning of the term “jury.” And since then, the Court has repeatedly held in a number of cases addressing topics ranging from the Confrontation Clause to sentencing factors that the history of the Sixth Amendment determines its meaning. By ignoring the historical backdrop from which the jury right was derived and relying instead on its finding that six- and twelve-person juries are “functionally equivalent,” the Williams decision is plainly at odds with long-standing Supreme Court precedent recognizing that it is the original understanding of the Sixth Amendment that controls its meaning, not some abstract functionalist analysis.

And Williams was wrong even on its own terms. Twelve- and six-person juries are far from “functionally equivalent.” Williams assessed the effect of jury size along three main dimensions: the quality of jury deliberations, the ability of the jury to properly represent a cross-section of the community, and the reliability of jury verdicts. But the studies Williams relied on for its determination that six-person juries performed just as well along these metrics were not studies at all, but mere conclusory statements based on anecdote. Worse, not only were these conclusions unsupported, they were demonstrably wrong at the time based on elementary statistics. Finally, numerous studies conducted since Williams was decided consistently show as an empirical matter that juries smaller than twelve are worse in every regard Williams identified as being essential to the Sixth Amendment’s jury trial right. To take just one alarming example, aggregating the results across five studies focused on minority representation in juries, researchers found that decreasing the size of a jury from twelve to six was the equivalent of decreasing the odds of minority representation from 2/3 down to 1/3. These studies have only underscored the wisdom of the Framers’ insight that a jury must be composed of twelve people.

If the Court hears Khorrami, it will have the opportunity to restore the original meaning of the Sixth Amendment’s jury trial right and ensure that no one can be convicted by a jury of fewer than twelve people. If not, criminal defendants like Ramin Khorrami will continue to be tried by juries much smaller than the Framers contemplated. And this is as wrong as it is dangerous—wrong as a matter of constitutional text and history, and dangerous because of the poor quality of justice that we know smaller juries deliver.