A trial to decide the legality of an Arizona law banning a Mexican-American studies curriculum from public schools has yet to receive a court date and probably won’t be heard until next year.

The delay marks a setback for the teachers and students of the prohibited classes, who view the Arizona state law as an unconstitutional and racially motivated attack on a curriculum credited by independent researchers with boosting student achievement in the majority-Hispanic Tucson Unified School District.

“We had hoped to get it to trial in October, but obviously that’s not going to happen,” Steven Reiss, one of the attorneys for the plaintiffs in the case, told The Huffington Post. “The case is clearly going to trial, the question is what will be included in the trial. I think it’s more likely than not that it will take place next year.”

Mia Garcia, a spokesperson for Arizona Attorney General Mark Brnovich, confirmed no trial date had been set, but declined to comment on pending litigation.

The discovery period ― a last step before trial in which lawyers for both sides of a case obtain evidence from each other ― is already complete. But attorneys for the state of Arizona want to exclude a claim that the ethnic studies law violates students’ First Amendment rights.

Attorneys for the state of Arizona also filed motions this week to keep three university professors with expertise in Latino history and the field of ethnic studies from offering expert testimony.

One of them, University of Arizona education professor Nolan Cabrera, spent years researching the effectiveness of Tucson’s banned Mexican-American studies courses. He co-authored a 2014 study published by the American Educational Research Journal, finding that those students who took the classes graduated high school at higher rates and performed better on state tests.

The effects of taking the classes were most pronounced for students who had previously performed most poorly and the positive effects extended to performance on state math exams. Because the Mexican-American studies courses weren’t offered in math, the researchers suggested the curriculum may have improved students’ overall relationship with school and education.

Efforts to disqualify expert testimony are typical in lawsuits. Even so, Arizona’s many challenges could delay the case for months.

“We don’t think the motions have any merit,” Reiss told HuffPost. “The elimination of the program had a bad impact on Mexican-American students. It took away a program that had helped increase their performance ... We ought to be very troubled when a class that was shown to help increase the performance of Mexican-American students is tossed away.”

The conservative-dominated Arizona Legislature passed a law in 2010 outlawing a Mexican-American studies curriculum in Tucson schools that some Republicans accused of instilling ethnic separatism by focusing on race.

The teachers of the banned classes denied those claims. They pointed out that an audit by Cambium Learning Inc., commissioned by then-Superintendent of Public Instruction John Huppenthal, recommended in 2011 that the classes be expanded and praised the instructors for teaching college-level critical thinking skills.

Ross D. Franklin/Associated Press Former Superintendent of Public Instruction John Huppenthal announces that Tucson's Mexican-American program violates the state law he helped pass in 2010. Huppenthal has also called for the abolition of the Spanish language from the United States.

But Huppenthal, who had helped pass the ethnic studies law as a state senator before taking control of the state’s public schools, discarded the Cambium report’s findings and declared the classes in violation of the new law. To comply, the local school board voted 4-1 in January of 2012 to discontinue the classes and carted off seven books that had been used in the curriculum, including Occupied America, a classic Chicano history textbook by professor Rodolfo Acuña.

A lawsuit brought by Tucson teachers and students coursed its way up to the U.S. Court of Appeals for the 9th Circuit, where a three-judge panel appeared skeptical that Arizona lawmakers enacted the law without intending to discriminate against the district’s Latino students.

In last year’s ruling, U.S. District Judge Jed Rakoff described Huppenthal’s decision to reject the Cambium report as “one of the most telling actions in this entire saga.” The panel sent the case to trial to determine whether Arizona officials had crafted and enforced the law with the intention to discriminate against Mexican-Americans.

The state ban on Tucson’s Mexican-American studies curriculum ironically sparked a wave of national interest in the program.

California passed a law earlier this month directing the state to create a model ethnic studies curriculum to guide local districts that want to implement the classes. Several of the state’s largest school districts ― including San Francisco, Los Angeles and San Diego ― already offer such courses.

Educators in some Texas districts have begun implementing Mexican-American studies courses along the lines of the Tucson program as well.

But Texas also faces controversy over whether to adopt a Mexican-American studies textbook that contains well over 100 errors that was commissioned by a religious zealot who once sat on the state’s board of education. A panel of Mexican-American studies experts views the textbook as fundamentally flawed and unsuitable for use in public schools.