Almost 15 years ago, a Republican president and Democratic congressional leaders forged a landmark education law. The law known as No Child Left Behind set strict requirements for academic achievement as measured by standardized tests. It was intended to hold teachers, principals and schools accountable for students’ progress. Schools that fell short would face real consequences.

The law succeeded in fits and starts, but it created a significant backlash in schools around the country.

To their credit, President Barack Obama and his education secretary, Arne Duncan, defended the basic principles of accountability in public education. They pressed a different effort, more carrots than sticks, through the federal initiative known as Race To the Top.

They took a lot of grief for this from traditionally Democratic constituencies. Last year, the National Education Association, the powerful teachers union, formally called for Duncan to resign. His great sin: promoting the evaluation of teachers and schools based on how their students learned, largely based on standardized tests.

Obama and Duncan held firm for nearly seven years, which is why what has happened in the last few weeks is so disappointing.

Duncan is stepping down as education secretary — on his timetable, not the NEA’s. But as he leaves, the Obama administration is softening its commitment to the strict scrutiny of schools and teachers based on how much their students learn.

The administration says it has heard the complaints that too much time in the classroom is being devoted to preparing for standardized tests.

The Council of the Great City Schools recently reported that the average student spends up to 25 hours a year taking about eight standardized tests. The average eighth-grader spends about 2.3 percent of classroom time taking standardized tests.

An Obama administration memo calls for a 2 percent cap on classroom time for standardized assessments. It wants Congress to set this limit in law.

The administration memo also appears to backtrack on using student test results in teacher evaluations, suggesting tests should be used more for information-gathering than as the backbone for accountability systems.

“I still have no question that we need to check at least once a year to make sure our kids are on track or identify areas where they need support,” Duncan said. “But I can’t tell you how many conversations I’m in with educators who are understandably stressed and concerned about an overemphasis on testing in some places and how much time testing and test prep are taking from instruction.”

Duncan even issued a mea culpa: “It’s important that we’re all honest with ourselves. At the federal, state and local level, we have all supported policies that have contributed to the problem in implementation. We can and will work with states, districts and educators to help solve it.”

We’ve heard the complaints from teachers and parents that test preparation takes too much time away from curriculum instruction. Schools do have latitude on this, though. In 2013, Chicago Public Schools scrapped a raft of standardized tests to help students focus on the most important ones, such as the annual statewide exam.

So what now? The U.S. House and Senate have passed sweeping overhauls of No Child Left Behind that would wisely continue statewide testing regimens, breaking out results among students by race, income and special needs.

However, both bills fall short on accountability. Obama has vowed a veto if the final bill doesn’t include powerful accountability measures. These bills would let state and local officials create their own performance standards and goals for schools. And if those schools faltered? Nothing would happen. The states wouldn’t have to push districts to improve, and the federal government wouldn’t have the authority to challenge states to enforce standards.

Take note: Scores this year on the National Assessment of Education Progress declined, the first drop in a quarter century.

It will be a terrible shame, a sad legacy, if the Obama administration caps its eight years of education reform efforts with a retreat from accountability.