The U.S. Supreme Court building in Washington, D.C. (Photo: Diego M. Radzinschi/ALM)

Most Americans would tell you that juries cannot convict someone of a serious crime if they are not unanimous. Surprisingly, two states have allowed juries to convict when all of the jurors did not agree. Many legal experts believe the U.S. Supreme Court is finally poised to declare that less-than-unanimous verdicts in state trials violate the Constitution. We urge the high court to once and for all expand the right to all the states.

The unanimity requirement was established in 1367, became the norm in England during the 15th century and has been the norm since. In the United States, 48 states and the federal government have always required jury verdicts to be unanimous for a criminal conviction. Only two states, Louisiana and Oregon, departed from the unanimity rule for reasons that many believe were discriminatory and shameful.

On the first day of the new term, Oct.  7, the Supreme Court will hold oral argument in Ramos v. Louisiana, which challenges Louisiana's outlier jury rule allowing a defendant to be convicted of a noncapital crime by a 11-1 or 10-2 jury verdict. Louisiana voters corrected this aberrational rule last year and now again require unanimity for future cases, but under the law at the time of Ramos' trial, he was convicted and sentenced to life in prison without parole, even though two jurors believed that he was not guilty.

In our view, Oregon's and Louisiana's jury rules are not entitled to deference because history shows they were adopted with the worst possible motives: to enable white majorities to disregard the voices of racial and religious minorities. Given the rule's indefensible history and continuing damage in the present day, the high court should not work to preserve it.

When Louisiana became a state in 1812, like every other state at the time, it required a unanimous vote of the jury to convict a defendant of a crime. Louisiana kept the unanimous jury rule in place for over 80 years but changed it after Reconstruction when some whites became concerned that African Americans would be able to serve on juries, vote and otherwise be a part of civic life.

Against this backdrop, Louisiana held a constitutional convention in 1898. The convention adopted literacy tests, poll taxes and grandfather clauses for voting. The new constitution also adopted a provision allowing less than unanimous juries to convict a defendant of a crime.

The U.S. Supreme Court has recognized that the purpose of the convention was to "assur[e] white political supremacy" in the state. (Louisiana v. United States 1965). A rule whose express purpose is to perpetuate white supremacy does not deserve to persist.

Louisiana was the only state to have a split jury rule until Oregon followed suit in 1934 after the public was outraged that a jury convicted a Jewish man of manslaughter instead of murder.

In Ramos' case, the court should not uphold a rule that was borne out of a discriminatory purpose and that broke from centuries of common law requiring unanimous jury verdicts. Any interest that the states may have in relying on prior court decisions must give way to the more compelling need to protect the constitutional rights of every citizen.

As Justice Neil Gorsuch said this year in United States v. Haymond, "Jury trials are inconvenient for the government. Yet, like much else in our Constitution, the jury system isn't designed to promote efficiency but to protect liberty."

The unanimous jury rule is both good law and sound practice. It ensures that a jury vote reflects the whole community and promotes public confidence in the criminal justice system. Perhaps most importantly, the unanimity rule requires citizens to deliberate carefully and listen to each other. As the actor Henry Fonda said in the classic movie "12 Angry Men," "We can't decide in five minutes. Supposing we're wrong?"

The court in Ramos' case should uphold the full promise of our Bill of Rights, apply the Sixth Amendment's unanimity requirement to the states and take a first step toward undoing the damage that this discriminatory rule has inflicted. This result would carry out the Framers' intent to codify the common law unanimous jury rule into our Constitution and, as John Adams wrote of the rule, "preserve the rights of mankind."

Richard Cullen, a former attorney general of Virginia, is a senior partner in the Government Investigation & White Collar Litigation department at McGuireWoods and a former managing partner at the firm. Stephen Bright is the former director of the Southern Center for Human Rights and currently teaches law at Yale, Georgetown and Georgia State University law schools.