Sen. Lamar Alexander (R-Tenn.), shown here in November 2014, called the atmosphere for compromise on revising the nation’s main education law “different” this time around. (Manuel Balce Ceneta/AP)

The Senate education committee voted unanimously Thursday in favor of a bill to revise the nation’s main education law, sending the measure to the Senate floor for consideration later this spring.

The 22-to-0 vote was an unusual example of bipartisanship in a Congress known for its polarization and gridlock. It gave many observers reason to believe that federal lawmakers might finally be able to reach a deal to rewrite the law known as No Child Left Behind, which expired in 2007.

“This has been a piece of legislation that has been seven years in the making,” said Sen. Lamar Alexander (R-Tenn.), chairman of the Health, Education, Labor and Pensions Committee. “We’ve never been able to get it to the floor, because we’ve not really agreed on anything. This time it’s different.”

The compromise bill would leave in place the requirement that states test students in math and reading in Grades 3 through 8 and once in high school. But it would significantly reduce the federal role in public schools.

States would still have to do something about low-performing schools, but it would be up to state officials to decide how to define a low-performing school and what, exactly, to do about them — a departure from No Child Left Behind, under which the federal government laid out an escalating series of sanctions for schools that persistently failed to meet academic targets.

Alexander and Sen. Patty Murray (Wash.), the committee’s ranking Democrat, spent months hashing out a bipartisan compromise, setting a tone of cooperation that continued as the committee marked up the bill this week.

The committee voted unanimously to adopt several noncontroversial amendments, including one to provide funds for states to audit their standardized tests to determine which are redundant or low-quality.

And senators on both sides of the aisle withdrew proposals that did not have bipartisan support, leaving intact the basic framework of the Alexander-Murray compromise.

Sen. Elizabeth Warren (D-Mass.) expressed deep reservations about the bill, saying that it fails to protect the interests of the nation’s most vulnerable students, including poor and minority students, students with disabilities and English-language learners. But she said she had “deep respect” for efforts by Alexander and Murray to work in good faith toward a better bill.

“It is in deference to those ongoing efforts that I am going to vote yes,” Warren said. “But I intend to fight for these changes when it gets to the floor, to ensure that this legislation . . . lives up to the promise that we once made in our landmark civil rights laws.”

The bill could still change significantly or stall before it hits President Obama’s desk.

A House bill to rewrite the law stalled in February, when a floor vote was canceled after conservative GOP lawmakers said it did not do enough to get the federal government out of local schools. Some conservatives have been critical of the Senate bill for the same reason.