Arne Duncan can go home now.

The education secretary will return to Chicago next week and leave government at the end of the month, having served longer than all but one of President Obama’s original Cabinet secretaries. (Only Tom Vilsack at the Department of Agriculture remains.)

On Wednesday, the Senate delivered the bill that Duncan has been seeking for nearly seven years, passing by 85-12 vote a rewrite of the George W. Bush-era No Child Left Behind education law. The House approved the measure in similarly bipartisan fashion last week, and Obama plans to sign it on Thursday morning at a White House ceremony. Whether the new law is a parting gift for the secretary or a kick on the way out the door, however, is a matter of some debate.

Duncan drew praise from Republicans like Newt Gingrich and Jeb Bush early in his tenure for his aggressive efforts to promote school reform. But over the years he has become a polarizing figure among conservatives, who accuse him of overstepping his authority by requiring states to adopt higher standards—like the Common Core—in exchange for federal money from the Race to the Top program and later, temporary waivers from the punitive sanctions in No Child Left Behind.

That anger led Republicans to demand provisions in the replacement law that specifically curtailed the education secretary’s authority. Future secretaries, for example, are forbidden from mandating or even incentivizing states to adopt particular standards like Common Core. The provisions led scholars like Frederick Hess at the American Enterprise Institute to describe the new Every Student Succeeds Act as a “repudiation” of Duncan and his way of doing business.

You might think the departing secretary would be cool to the bill, if not downright bitter about the congressional stripping of his department’s power. But in an interview earlier this week, Duncan was practically jubilant.

“If you look at the heart of the bill, it absolutely reflects our values and priorities,” he told me.

The compromise hashed out over the last few months is a reflection of the fact that both parties came to believe that No Child Left Behind had gone too far and more importantly, that the waiver system Duncan implemented to shield states from its harshest penalties had caused a torrent of frustration across the country. The new law returns significant power to the states to develop their own accountability standards for schools, repealing the requirement that schools demonstrate “adequate yearly progress.” But it doesn’t eviscerate the federal role entirely.

The legislation maintains the requirement for annual testing, and it requires the Department of Education to sign off on state-developed plans for improving when states fail to improve their lowest 5 percent performing schools and high school “dropout factories.” It prevents states from exempting more than 1 percent of students from their main annual tests, and it mandates that states report performance data broken out by subgroups based on factors like income, race, language barriers, and learning disabilities—a tool advocates consider crucial for addressing the achievement gap. And in a victory for the Obama administration and congressional Democrats, the law includes $250 million in annual funding for early childhood education, although it is housed not in the Department of Education but in Health and Human Services.

Perhaps most importantly to Duncan, the law codifies the idea that states must develop standards to make students “college and career-ready.” “This is the first time in the history of the nation that college and career-ready standards are going to be the law of the land,” Duncan told me. “That’s a massive breakthrough.”

Yet Congress leaves it to the states to define what those mean, and Duncan acknowledged that the added flexibility offers “both the greatest opportunity and the greatest risk.” “If they focus on real long-term outcomes, then this is going to be a huge step in the right direction,” Duncan said.  “If states resort to softer things and walk away from real outcomes for kids, that’s the risk.”

And what about those restrictions on secretarial authority? Duncan didn’t want to talk about those provisions on the record. But Democrats in the White House and on Capitol Hill characterized them as “talking points” for Republicans and say they worked with lawyers to water them down. In a victory-lap speech on Tuesday, Duncan said a focus on his own power “fundamentally misses the point.”

It wasn’t about what power I had. It was about what kind of opportunity Brandon, Russhaun, Federico Christina and Star have. Throughout our nation’s history, the federal government has played an important role in protecting their civil rights. And despite the rhetoric, the law that the House passed last week, and that the Senate is considering today allows us to continue to play that critical role in the lives of students across the country.

Representative John Kline, the chairman of the House Education and the Workforce Committee and a lead Republican negotiator, argued that the restrictions on federal authority—and specifically the secretary—were significant. “We spent about 50 pages in this bill putting very strict prohibitions on what the secretary can and cannot do,” he said in a phone interview. “There are some things in there that I’m sure Arne Duncan likes. But there’s also a lot in there to keep this education secretary or any education secretary from writing their own policy. That’s very important.”

Critics of the new law characterize Duncan’s embrace of the Every Student Succeeds Act as something close to delusional. “Arne, they leveled your office and program. Why are you celebrating it,” tweeted Sandy Kress, a former education adviser to President Bush and an architect of No Child Left Behind.

He elaborated on his critique in a blog post on Wednesday.

While annual testing and the provision for states to put together accountability plans with certain features continues to be required, this legislation fundamentally finishes off the evisceration of accountability begun by the administration four years ago.

The secretary will have virtually no authority to enforce the meager “requirements” that remain, and the federal government will have no power whatsoever to require any consequences for schools that fail to lift student achievement or close achievement gaps.

In many respects, the debate over federal education policy is a question of trust, and the Republicans now running Congress trust the states.

“I think we just have to have confidence that the states have learned over these last years,” Kline told me. “I don’t subscribe to the notion that only the federal government cares about how well these kids do.” The Senate education chairman, Lamar Alexander, predicted in a floor speech that the new law would “unleash a flood of innovation and student achievement across America.”

As recently as this summer, it seemed unlikely that Congress would be able to agree to a broad education bill after so many years of trying. The Senate had passed a bipartisan measure, but the House version was seen as much more conservative. Kline argued, however, that the odds were never that low. He said the frustration with the status quo waiver system had increased the urgency to compromise. “It turns out the principles were shared in kind of a bipartisan way,” he told me. “We wanted to reduce the federal imprint that came with No Child Left Behind, a huge intrusion by the federal government. We wanted to restore local control, and we wanted to empower parents with some choices. And we got all those things in the bill.”

The dispute over secretarial authority aside, Kline’s statement would draw little protest from Duncan, who professed shock that the bill actually got stronger in his view after the House and Senate reconciled their proposals. The final measure passed with unusually broad support and little vocal opposition, with just 12 opponents in the Senate and 64 in the House. Federal education policy is often far removed from the day-to-day reality in America’s classrooms, and it will take years to determine if this new approach yields improvements. But judging by the vote in Congress, it appears that a bipartisan consensus on education policy in Washington has, however briefly and for good or ill, been restored.