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 Wednesday rejected an amendment to its No Child Left Behind rewrite that had been championed by major civil rights groups as necessary to ensure that schools are serving the nation’s most disadvantaged children.

The chamber voted 54 to 43 against the amendment, which aimed to give the federal government more say in defining which schools are low-performing and require intervention.

Instead, the bill allows states to decide not only how to judge schools’ success, but which schools don’t measure up and what to do to improve them.

The proposed amendment’s lead sponsor, Sen. Chris Murphy (D-Conn.), said that could return the country to the days when states and school districts could ignore achievement gaps and allow poor, minority and disabled children to languish.

“This law is an education reform law, but it has to be a civil rights law as well,” said Murphy, invoking the law’s original passage in 1965 as part of President Lyndon Johnson’s War on Poverty.

The measure was opposed by many Republicans who want to rein in the federal government’s influence over education, which they say ballooned under the Bush and Obama administrations.

“Instead of fixing No Child Left Behind, it keeps the worst parts of it,” said Sen. Lamar Alexander (R-Tenn.), chairman of the Senate education committee.

Democratic lawmakers in both chambers are sure to continue pushing for stronger accountability provisions before sending the legislation to the White House. Education Secretary Arne Duncan has said that the Obama administration would not support the legislation unless it strengthens the federal role in school accountability. But he stopped short of saying whether the president would veto it.

The unsuccessful amendment would have required states to identify and take action in:

• The lowest-performing 5 percent of public schools, as determined by the state;

• High schools where fewer than 67 percent of students graduate on time; and

• Any school where poor, disabled, minority or English-language-learner students do not meet state-set achievement goals on standardized tests and other measures for two consecutive years.

The National Education Association, the country’s largest teachers’ union and traditionally an ally of Democrats, had also mobilized against the measure, arguing in a letter to lawmakers Tuesday that it “would continue the narrow and punitive focus” of No Child Left Behind.

The NEA was particularly opposed to requiring intervention at schools where subgroups of students are not meeting targets. The union said that requirement would result in an over-identification of failing schools, repeating a key problem with No Child Left Behind.

Kati Haycock, president of the Education Trust, accused the union of working to protect suburban schools that perform well on average but where disadvantaged children persistently lag behind, from change.

“Clearly, NEA President Lily Eskelsen Garcia wants to claim the mantle of civil rights and social justice — words that are sprinkled throughout her speeches — while simultaneously freeing her members of the responsibilities of improving outcomes for the most vulnerable children,” Haycock wrote in a blog post.

An NEA spokeswoman said Eskelsen Garcia was traveling Wednesday afternoon and could not be reached for comment.

Senators are expected to vote on the main bill this week.