Shelly Centanni, Marketing and Parent Outreach Manager at University View Academy, shows a banner set up at events to promote the school at information seminars, teacher fairs and graduations, Friday, May 5, 2017, during a tour of the state’s largest online charter school, at which high school students will be able to be set up with dual enrollment courses through local community colleges, with the goal of getting them associate degrees at the same time as their high school diplomas.

The Louisiana Supreme Court sided with charter school backers Tuesday in a lawsuit that had threatened state aid for about 18,000 students.

The funding method had been challenged by the Louisiana Association of Educators, one of the state's two teacher unions.

The high court, in an 18-page ruling, reversed a 3-2 decision by the Louisiana First Circuit Court of Appeal. The appeals court held last year that the funding was unconstitutional because the schools did not meet the legal definition of public schools.

"While there is no definition of public elementary and secondary schools in the Constitution, our Legislature has expressed that charter schools are independent public schools," according to the Supreme Court ruling, written by Justice James T. Genovese, of Opelousas.

The state's top court said critics of the funding "failed to carry their burden of proving clearly and convincingly" that allocating traditional school aid dollars to the schools was illegal.

The case applies to 35 charter schools authorized by the state Board of Elementary and Secondary Education after unsuccessful efforts by non-profit groups to win authorization from local school boards. The state aid under fire accounts for up to 90 percent of dollars the schools get, officials said.

Charter schools are public schools run by non-governmental boards.

About 80,000 students attend around 145 charter schools statewide. Louisiana has about 700,000 public school students.

State Superintendent of Education John White told reporters the legal challenge was simply aimed at shutting off the flow of state dollars for the schools, and forcing parents and children to look elsewhere.

"This lawsuit has always been about money, plain and simple," White said. "It was never about children."

He added, "The plaintiffs were hoping that these schools would be driven out of existence. There is no other way to explain this lawsuit."

Debbie Meaux, president of the LAE, said in a statement that she was disappointed in the decision. "This ruling solidifies the division of public schools into separate systems, creating greater inequities for our students," Meaux said.

The ruling will prevent what could have been a major battle in the Legislature.

If backers of charter schools had lost, they would have tried to remove about $70 million from the state school aid program to fund the schools under fire.

That would have resurrected bitter arguments about the merits of the schools amid yet another state financial crisis and short tempers in the Legislature.

The Iberville Parish School Board joined the LAE in the legal challenge, arguing that local tax dollars for traditional public schools were improperly diverted to the charter schools.

The ruling was 5-2 with Justice John L. Weimer, of Thibodaux, concurring but spelling out different reasons for the majority decision.

Others in the majority were Justice Genovese; Justice Greg Guidry, of Jefferson Parish; Justice Marcus Clark, of West Monroe and Justice Scott Crichton, of Shreveport.

Dissenting were Chief Justice Bernette Johnson, of New Orleans and Justice Jeff Hughes, of Walker.

The scoop on state politics in your inbox

Get the Louisiana politics insider details once a week from us. Sign up today.

Charter school backers, who had been waiting for a ruling for more than five months, were jubilant over the news.

"I am so thrilled," said Caroline Roemer, executive director of the Louisiana Association of Public Charter Schools.

Echoing White, Roemer said the lawsuit "is not about children. This is not about quality of education. This comes down to nothing but money."

In her dissent, Chief Justice Johnson disputed the majority's view that the schools meet the legal definition for public schools. "Historically, we have defined public schools as elementary and secondary schools operated and administered by a locally elected parish or city school board which provides free and open enrollment to every child in the school district," she wrote.

Justice Hughes said MFP dollars, the state formula that determines funding for public schools, should not be used to finance these charter schools. "Short cuts around the Constitution, even for what may seem laudable or politically expedient, are inimical to democracy and are not cool," Hughes wrote.

The president of the Louisiana chapter of praised the ruling.

"Today's Supreme Court ruling was the right one, affirming the rights of parents to choose the educational option that works for their children," said Christin White-Kaiser, president of the group and the parent of a child who attends one of the schools.

"This lawsuit from the union bosses was always about money and never about what was in the best interest of students," White-Kaiser said in a statement.

White-Kaiser said last year that, in the event of an adverse court ruling, she would likely home school her daughter Mary Grace, a Jefferson Parish student who, like others, was caught in the middle of the legal challenge.

The ruling ended a court fight that began in 2014.

Backers of the schools won the first round when 19th Judicial District Court Judge Wilson Fields, of Baton Rouge, ruled in 2015 that the funding was legal.

The First Circuit Court of Appeal last year narrowly reversed that decision, putting the future of the schools in doubt.

Periodically officials on both sides of case predicted a Supreme Court ruling was imminent, including a wide range of such predictions last  October.

The schools whose funding was under fire include Madison Preparatory Academy in Baton Rouge; International High School in New Orleans; Lycee Francais de la Nouvelle-Orleans in New Orleans; Louisiana Key Academy in Baton Rouge; Acadiana Renaissance Charter Academy in Lafayette; JCFA-East in Jefferson Parish and University View Academy in Baton Rouge.

Meaux said attorneys for the LAE will meet to decide next steps.

White said he is satisfied that the Supreme Court ruling ends the case.

Gov. John Bel Edwards' office did not  respond to a request for comment.

Follow Will Sentell on Twitter, @WillSentell.