(CNN) -- Arizona schools superintendent John Huppenthal has told the Tucson district to stop teaching its controversial Mexican-American studies program or face losing $15 million in annual state aid under a new law, he said Tuesday.

Huppenthal told CNN he was backing this week's decision by exiting state superintendent Tom Horne giving the state's second largest district 60 days to comply with a new 2011 law banning certain ethnic studies programs in public schools.

Horne is now Arizona's new attorney general, and Huppenthal was sworn in Monday as the newly elected Arizona schools superintendent. Both men are Republicans.

The new schools law is the latest controversy in a state already roiled by an immigration crackdown law, known as SB 1070, that is being challenged on constitutional grounds in federal court. The Arizona-Mexico border is considered the nation's busiest for illegal immigration.

Tucson school board member Adelita Grijalva charged that the new law provided no due process and was unconstitutional. She said the new law was part of an anti-immigrant political climate in the Arizona statehouse. She and Huppenthal said they expected this new law to also end up in court.

"People of color in the state of Arizona are under attack," Grijalva told CNN. "We're basically going from one battle to the next."

The law authorizes the state superintendent to stop any ethnic studies classes that promote the overthrow of the U.S. government, promote resentment toward a race or class of people, are designed primarily for pupils of a particular ethnic group or advocate ethnic solidarity instead of the treatment of pupils as individuals.

In written findings Monday, Horne said the Tucson program violated all four criteria.

Huppenthal said the Tucson program is "in clear violation" of the new law because they're designed for pupils of a particular ethnic group.

Tucson educators who have challenged the constitutionality of the new law in court have defended the Mexican-American studies program as no different than African-American or Native American studies classes.

Added Grijalva: "What we're doing is teaching a course that is a history course with a Mexican-American perspective. I don't understand what is so scary about that concept."

Huppenthal, who was a state legislator for 18 years and was the chairman of the Arizona Senate education committee, said he was serious about enforcing a $15 million-a-year penalty that both sides agree would devastate Tucson schools, if the district doesn't end the ethnic studies program.

That penalty is 10 percent of the state's aid to the Tucson system, whose total operating budget is $450 million a year, officials said.

"Make no doubt about it. They shouldn't be under any illusion on this thing," Huppenthal told CNN. "We're going to proceed forward. These are serious issues."

The Tucson Unified School District's governing board has told the state in a letter that it "supports" the classes, which it says complies with the new law.

"TUSD administration supports its ethnic studies programs, and we are encouraged by the real and lasting impact that these programs provide to all TUSD students," the letter stated, according to the board's website.

Also Monday, Tucson superintendent John Pedicone told administrators and employees that he wouldn't tolerate any student walkouts protesting the state superintendent's actions.

Pedicone also encouraged principals to arrange a time in the school gym for students to "express their view and discuss the pros and cons of the new law in a constructive manner," he said in a letter that was posted on the system's website.

"If a student leaves campus to participate in a protest or walkout, there will be consequences in accordance with school procedure and governing board policy," Pedicone said.

Huppenthal said he observed one of Tucson's ethnic studies classes last year.

"When I came into a classroom, they were portraying Ben Franklin as a racist," Huppenthal said. "Ben Franklin was the president of the Abolitionist Society in Pennsylvania. ... So they are vilifying Ben Franklin in this classroom, and up on the wall, they got a poster of Che Guevara, and the historical record is that he helped direct the communist death camps in Cuba by killing many dissidents.

"We just have a lot of concerns about the classes," Huppenthal said.

Huppenthal said he was going to broaden his public discussion about the Tucson district to include how some Tucson public schools, particularly those serving low-income minority students, are among the worst in the country. He said he was planning a new accountability system measuring the performance of each school district.

"When we do our rankings and compare the data, a number of the schools in the Tucson Unified School District are among the bottom three in the nation," Huppenthal said.

"In their failure to serve these kids academically, we see the same failure in their response to the community concerns about these (ethnic studies) classes," Huppenthal added. "I'm a fan of Ronald Reagan and he primarily relied on persuasion. I want to use the energy associated with this one issue to get the Tucson Unified School District to examine itself."

Tucson's ethnic studies program, created in 1998 and initially called "Mexican American/Raza Studies," has been effective in reducing dropout rates among Latino students, as well as discipline problems, poor attendance and failure rates, teachers said.

In October, 11 Tucson teachers sued the state board of education and superintendent over the new law, calling it an "anti-Hispanic" ban on Mexican-American studies.