When Evangelisto Ramos was convicted of murder in 2016 in Louisiana state court, not all of the jurors voted to convict him.

At the time, Louisiana only required 10 of 12 jurors to vote guilty for a conviction. Now, the U.S. Supreme Court has agreed to hear Ramos' arguments that such nonunanimous verdicts are unconstitutional.

It's a case that could end nonunanimous jury verdicts in Oregon, the only state left to still allow them, and make the prohibition retroactive in Louisiana, which recently voted to require unanimous juries. That means that people like Ramos, who were convicted before the law went into effect, could ask for new trials.

"We are hopeful the court took the case to restore the full protections of the Constitution to the state of Louisiana," Ben Cohen, an attorney for Ramos, told Law360. "We think the court will understand what the people of Louisiana have grown to understand — that we are a stronger, better country, when the Constitution is given its full meaning, when the voice of every juror matters."

According to Aliza Kaplan, a professor at Lewis & Clark Law School who has studied the issue, Louisiana and Oregon are the only states to have allowed criminal defendants to be convicted by a nonunanimous vote. And in both states, the practice is rooted in discrimination, Kaplan said.

"In Louisiana, it was a way to convict more African-Americans so they could [be made to] work after slavery was ended," she said. "In Oregon ... it was a time when there were a lot of [Catholic and Jewish immigrants] and there was a lot of discrimination against immigrants."

The policy in Oregon, she said, was passed after a high-profile 1930s murder trial in which a Jewish man was not convicted.

By allowing only 10 of 12 jurors to convict, both states were able to nullify the votes of black jurors and other racial or ethnic minorities, allowing for more convictions.

It's an issue that does not exist at the federal level. The U.S. Supreme Court has long held that the Sixth Amendment, which guarantees the right to a trial by jury, requires unanimous verdicts in federal criminal trials. However, in 1972 the court ruled in the case Apodaca v. Oregon that the states were not held to the same requirement.

It was an unusual decision in light of the 14th Amendment's guarantee that the protections in the Bill of Rights should also apply at the state as well as federal level. In his petition, Ramos called for the court to overturn Apodaca, saying that it goes against other decisions the high court has issued and that the legal reasoning it relies on has since been abandoned.

He previously argued his case before a Louisiana state appellate court and lost the appeal. The Louisiana Supreme Court declined to hear his case, but the U.S. Supreme Court agreed to take it up on March 18.

The state of Louisiana has argued that Apodaca rested on a historical understanding of what the framers of the Constitution would have understood a jury trial to entail.

"History," its brief to the high court argued, "has not changed."

The brief also pointed out that during the passage of the Sixth Amendment, language that would have required unanimous jury verdicts was removed, suggesting the framers did not want to impose the requirement.

The state argued as well that even though it is documented that the officials who drafted the original policy in 1898 had racist motivations, that did not automatically mean that every policy proposal they put forth should be seen as racist. In fact, the brief said, the state reaffirmed the nonunanimous jury policy in 1974 based on arguments for judicial efficiency.

Attorneys for the state did not respond to a request for comment.

Although the justices are likely to focus on the legal aspects, the case also brings up practical concerns, too. Louisiana highlighted that ruling that nonunanimous juries are unconstitutional would allow anyone convicted by a nonunanimous jury to petition for a new trial, potentially leading to thousands of cases — some of them decades old — being reopened and flooding the court system.

However, William Snowden, the director of the New Orleans office of the Vera Institute of Justice and founder of the Juror Project, which both back the Louisiana referendum requiring unanimous juries, said that he doesn't think this is a reason not to let people petition for new trials.

"That is what is owed to these individuals if in fact the Supreme Court finds that we've been operating our courts and our trials in an unconstitutional way," he said. "The mere fact that it would create a lot of work [shouldn't make us] afraid of ... redressing past injustices."

The scale of that potential impact is also uncertain and will depend on the court's exact ruling. According to Beth Heckert, president of the Oregon District Attorney Association, attorneys in Oregon state court must ask to poll the jury in a criminal case to determine whether the conviction was unanimous or not, meaning it's hard to get firm statistics on the number of nonunanimous convictions.

In addition, she said, murder charges in Oregon do require a unanimous verdict, though other felonies require only 10 out of 12 jurors to convict. So if the high court issues a narrow ruling that only prohibits nonunanimous verdicts in murder trials like Ramos', it won't have an impact on Oregon, she said.

However, she said, if the court does issue a broader ruling that would allow for convicted Oregon defendants to petition for new trials, that could strain courts' and DA's offices' resources and would be difficult for victims who believed their cases were settled.

She said that the ODAA believes that the issue is something that should be decided by the voters, as some groups have proposed in Oregon.

"If there is a perception that somehow not having a unanimous system builds in inequities, that's something we should change," she said. "That's what the voters should tell us."

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--Editing by Katherine Rautenberg.