THERMAL, Calif. — At Las Palmitas Elementary School, nestled between rundown homes and fields of grapes, peppers and dates in Southern California, 99 percent of students live in poverty and fewer than 20 percent speak English fluently.

Las Palmitas and other schools in the Coachella Valley Unified School District are just the type policy makers had in mind when Congress passed the federal No Child Left Behind Act in 2001 to shed light on the disparities facing poor and minority children.

Nineteen of the district’s 21 schools — including Las Palmitas — have not met the federal law’s performance benchmarks for four years. Now the entire district faces sanctions for the first time.

“We have hardworking, dedicated, trained teachers like everybody else. They’ve got to teach a language, they’ve got to teach the content, and they’ve got to counter poverty,” said Foch “Tut” Pensis, the district’s superintendent. “We are the poster child for NCLB.”

California has 97 school districts that failed to meet their goals under the law for four years, more than twice as many failing districts as any other state so far. Kentucky has the next highest number facing sanctions, with 47.

Nationwide, 411 school districts in 27 states now face intervention.

Over the next few years, hundreds more districts are destined to enter the next phase that California already has begun. The state has ordered districts to undergo everything from reporting how they are implementing the federal law to having a team of specialists assess every aspect of their operations. In the most extreme cases, California districts could be subject to a state takeover.

How California and the other states will turn around those struggling districts is unclear.

“No one, on a large scale, has figured out how to solve the achievement gap,” Pensis said. “Everybody’s looking for that answer.”