Sen. J.P. Morrell, D-New Orleans, center, jabs his finger onto the testimony table for emphasis during debate on his SB243 by the House Criminal Justice Committee at the State Capitol, Wednesday, April 25, 2018. At left is Rep. Edmond Jordan, D-Baton Rouge, and at right is Alexandria attorney Ed Tarpley, left, former District Attorney for Grant Parish, who had earlier testified in favor of the bill.

A referendum to do away with a Jim Crow-era law that allows juries in Louisiana to convict suspects in felony trials without a unanimous vote has won the backing of the state Republican Party, a key endorsement that seemed far-fetched only a few months ago.

The state GOP’s Central Committee voted 78-17 in Lafayette on Saturday to encourage Louisiana voters to join 48 other states in requiring unanimity to convict or acquit a criminal defendant in all felony trials.

Louisiana and Oregon are the only states that allow juries to return verdicts where there is dissent. Both states allow as few as 10 of 12 jurors to decide a case. And only Louisiana, the first state to break from centuries of Anglo-Saxon legal tradition on jury unanimity, allows split verdicts in murder trials.

The state GOP's endorsement follows a surprise run through the Legislature for a bill authored by Sen. JP Morrell, D-New Orleans. Given little chance in March, the proposed constitutional amendment quickly gained steam after the powerful Louisiana District Attorneys Association dropped its formal opposition.

Needing two-thirds support in the Legislature, the measure cleared its final hurdle in the House by a vote of 82 to 15.

State voters will now decide Nov. 6 whether to dispense with a rule that was born in 1898 at a constitutional convention steeped in the rhetoric of white supremacy. The referendum itself needs a simple majority to pass.

Tilting the scales: What to know about Louisiana's controversial non-unanimous jury law

In a statement, Andrew Bautch, executive director of the state GOP, quoted John Adams, the American founding father who once said it was "the unanimity of the jury that preserves the rights of mankind." 

The state party "feels it's time to adopt this amendment," Bautch said. "I along with our governing body believe that in criminal cases, the verdict of the jury should be unanimous.”

Gov. John Bel Edwards, a Democrat, already has stated his support for the referendum, describing Louisiana as “an outlier when we shouldn’t be.”

The state Democratic Party has yet to weigh in formally but is all but certain to endorse the proposal in late summer, said its executive director, Steven Handwerk. “I have no doubt in my mind," Handwerk said.

Ben Cohen, an attorney with the Promise of Justice Initiative who has filed numerous challenges to the constitutionality of the current system, called the GOP's support a sign of “almost universal recognition that unanimous juries are central to our constitutional system. We are stronger, our criminal justice system is stronger, when every voice is valued.”

In the meantime, reform advocacy groups have begun organizing a campaign in support of the referendum.

Their first salvo came last week, in a billboard that appeared above a strip mall in Calcasieu Parish, mocking the district attorney there, John DeRosier, for his defense of the split-verdict law during a House committee hearing.

“I’ve heard a lot about this being a vestige of slavery,” DeRosier told the committee. “I’m not proud of that, and I have no reason to doubt it. But it is what it is.”

Black committee members, led by state Rep. Ted James, D-Baton Rouge, seized angrily on that comment. 

Momentum builds to put unanimous-jury issue on ballot; applause erupts as bill advances

In an interview last week, DeRosier insisted his comment was misconstrued. He said he was agreeing that the racist history of the law “can’t be defended,” while arguing that there’s no evidence that non-unanimous verdicts are less reliable than those reached by every member of a jury.

“It’s a little bit frustrating,” he said of the billboard, which was paid for by a San Francisco-based advocacy fund. “It attempts to try and convince some other people that (his comment) was something sinister, when it absolutely was not.”

A divided U.S. Supreme Court upheld the split-verdict laws in both Louisiana and Oregon in 1972, ruling that federal juries must be unanimous but that states were free to tinker with their own jury rules.

Some defenders of the split-verdict rule have argued that Louisiana "cleansed" its law when delegates met in 1973 to craft a new state constitution and agreed to require 10 votes for a valid verdict, up from nine.

But an Advocate review of nearly 1,000 jury trials in Louisiana over a six-year period found that the law continues to disadvantage black defendants more than white ones.

About 40 percent of the convictions in the newspaper’s review came with one or two holdout jurors, and black defendants were 30 percent more likely than white ones to be convicted by split juries.

In East Baton Rouge Parish, where the newspaper examined the votes of individual jurors in most cases, records show that black jurors were 2.5 times more likely than white ones to vote against conviction in cases with split verdicts.

Staff writer Jim Mustian contributed to this report.

Follow John Simerman on Twitter, @johnsimerman.