Sen. Lamar Alexander ( R-Tenn.) and Sen. Patty Murray (D-Wash.) crafted the bipartisan bill to rewrite No Child Left Behind. (Susan Walsh/AP)

The Senate on Thursday passed a bipartisan rewrite of No Child Left Behind, the main federal education law, that would shrink the federal role in the nation’s 100,000 public schools and yield greater power to states to judge student achievement and school performance.

The measure passed 81 to 17, an unusual level of agreement in a hyperpartisan era on Capitol Hill. It was a victory for Sen. Lamar Alexander (R-Tenn.) and Sen. Patty Murray (D-Wash.), who navigated divides within their parties to push the measure to passage, which lawmakers have been unable to do for eight years.

Alexander dryly called it “a remarkable accomplishment for a U.S. Senate filled with 100 experts on education.”

But the bill lacks a key accountability measure important to Democrats and the Obama administration: an amendment that would have defined struggling schools and compelled states to act to improve them.

Democrats said they would work to get that part included during negotiations with the House on a final bill.

Under the Senate bill, states would still be required to test students annually in math and reading from grades three through eight and once in high school. And they still must report those results by categories of race, income, ethnicity, disability and English-language learners.

But in a departure from the current law, it would be up to the states to determine if a school is struggling or failing to educate any particular group of students, and states would decide what action to take.

Democrats and civil rights groups said that would allow states to ignore disadvantaged students — those who are the most difficult or costly to educate.

Leslie Proll, director of the Washington, D.C., office of the NAACP Legal Defense and Educational Fund, said the bill undermines the intent of the original federal education law from 1965.

“It’s simply unfathomable that 50 years after its passage, Congress would consider gutting its primary purpose: to ensure that those who are serving our children are doing so on an equitable basis,” she said. “Yes, transparency and data are good, but information alone without requiring specific action for addressing disparity does great damage.”

Education Secretary Arne Duncan said the bill would give states important flexibility and reduce overtesting, but he agreed with civil rights groups that it lacked adequate protections for disadvantaged students.

“We need to identify which schools work and which ones don’t, so we can guarantee that every child will have the education they need,” Duncan said in a statement. “We cannot tolerate continued indifference to the lowest performing schools, achievement gaps that let some students fall behind, or high schools where huge numbers of students never make it to graduation.”

The Senate bill would significantly reduce the authority of the U.S. Department of Education, prohibiting the secretary from influencing state academic standards and assessments, requiring teacher evaluations or prescribing what states must do to address failing schools.

Conservatives called it a victory for state and local control.

“People closest to the children cherish their children,” Alexander said. “We should not assume just because we fly to Washington once a week, we are so much wiser.”

In an unusual alliance, the National Education Association, the nation’s largest teachers union, joined with Republicans to push back against the accountability proposal favored by Democrats and civil rights groups. The union’s president, Lily Eskelsen Garcia, called the bill a “giant leap forward for childkind” because it would reduce the role of standardized testing.

The move comes a week after House Republicans pushed through an education bill without a single Democrat voting to support it. The House version earned a veto threat from President Obama because it would change how the federal government distributes funds designed to help educate poor children in a way the White House believes would harm them.

The simultaneous action in both chambers is notable because for eight years, Congress has sputtered to rewrite No Child Left Behind, which President George W. Bush signed into law in 2002 and was due for reauthorization in 2007. The law became increasingly unworkable and widely despised by school districts, states and even federal officials.

“It’s certainly not the bill that [President Obama] would write if he were writing it,” Alexander said. “It’s certainly not the bill that Sen. Murray would write if she were writing it, and it certainly would not be the bill I would write if I were writing it. But we have a consensus that we need to come to. And why do you need a consensus? Because that’s how you govern a complex country.”