Presidents George W. Bush and Barack Obama deserve praise for efforts to shake up the nation's tethered-to-the-past public school system.

Thanks to their involvement and bully pulpits, public school districts across America have been held accountable for how well -- or how poorly -- they teach our youth.

But school districts perform best when local leaders are free to tailor curriculum and discipline to the specific needs and aspirations of their students.

This is one of the lessons taken from the success of the much-admired school system in Union City, N.J., where immigrant children are graduating from high school and going on to college in high numbers.

We have a similar success story here in the central San Joaquin Valley. The leadership of Superintendent Marc Johnson and the hard work of teachers have elevated Sanger Unified, a district where about 43% of students are English language learners, into a top district.

Like Union City, Sanger Unified has raised student expectations and performance by putting together its own plan.

We believe that Sanger, Clovis and Fresno unified school districts are taking the right step in applying for waivers from the federal No Child Left Behind accountability rules.

We also believe that the superintendents of these districts are on the mark in seeking local accountability measurements and additional flexibility to best prepare students to succeed at work or in a university setting.

It's not that the No Child Left Behind Act, signed into law in 2001 by Bush, is a failure. The act put a needed focus on teacher performance and gave parents the freedom to move children out of poorly run schools in their neighborhoods.

But No Child Left Behind places too much emphasis on standardized testing instead of evaluating a student's learning and maturation in their entirety.

Schools shouldn't be shackled by federal rules that too narrowly define success, don't accurately account for the hurdles facing poor and English-language learners and apply sanctions -- instead of lending aid -- to struggling districts.

Clovis and Sanger are first-rate school districts. When their leaders say that No Child Left behind is counter-productive, we believe them.

They, as well as Fresno Unified, should have more freedom to pursue what works best for their students.