Education Secretary John B. King Jr. is leaving his department to a successor with a radically different philosophy about the role of government in schools. (Andrew Harrer/Bloomberg)

The fiercest critics and most ardent supporters of President Obama’s Education Department — which has arguably wielded more influence and sparked more controversy than any of its recent predecessors — generally agree that the agency’s efforts were rooted in the faith that government has a critical role to play in improving people’s lives.

Now the department is poised for a radical shift with the arrival of Donald Trump in Washington; the businessman, now president-elect, has often spoken about government as a bumbling failure and an impediment to success.

Education Secretary John B. King Jr. — who says public schools saved his life after he was orphaned young — is preparing to move out of his seventh-floor office suite at the department’s D.C. headquarters. His designated successor, Betsy DeVos — a billionaire political power broker who has said public schools are a dysfunctional monopoly and who believes in private-school vouchers and the power of the free market — is preparing to move in, her confirmation hearing set for Tuesday.

“Government can be a tremendous force for good,” King said in an interview at his office recently.

“Government really sucks,” ­DeVos, Trump’s nominee for education secretary, said last year at the South by Southwest educational technology conference in Austin. “And it doesn’t matter which party is in power.”

Education Secretary-designate Betsy DeVos has said public schools are a dysfunctional monopoly. (Andrew Harnik/AP)

It is this ideological divide as much as any other that is at the root of what Trump has promised will be a very different approach to the nation’s public schools. He has said he will shrink federal oversight and interference and wants to spend billions of dollars to encourage vouchers — which the Obama administration has vigorously opposed — and charter schools.

Obama administration allies worry that Trump’s approach will overturn much of the work from the past eight years, from its re­invigoration of the civil rights division responsible for investigating complaints of discrimination to its crackdown on for-profit colleges accused of defrauding students.

But King, a former U.S. history teacher who once wrote lessons about democracy and is now viscerally experiencing it, steadfastly refuses to speculate about what the next administration might do. Following Obama’s lead, he speaks only obliquely about the dis­appointment over election results that endanger his legacy, using Obama’s language about history never moving in a straight line toward justice but zigging and zagging along the way.

And he says he believes the administration’s work has created momentum — to expand public preschool offerings, to prevent and appropriately handle campus sexual assault — that will continue in schools, cities and states regardless of what happens in Washington.

“The next administration and Congress may do some things differently,” King said. “But in some ways, the culture has been fundamentally changed.”

The battle over the role of the federal government has been a central tension in U.S. public ­education for decades, from the desegregation of the Jim Crow South to battles over prayer in classrooms.

Republican President George W. Bush was a proponent of a strong federal role in schools through the testing and school improvement mandates of the No Child Left Behind law, which he said was necessary to address the “soft bigotry of low expectations.”

Not since President Ronald Reagan — who said he wanted to do away with the Education Department — has the executive branch been so openly skeptical of the federal role in education. And while Reagan had to deal with a Democratic Congress, no such partisan roadblock stands in the way of Trump, who also has professed an interest in dismantling the department.

Many of the items that King ticks off as recent accomplishments — vigorous civil rights enforcement, new rules for teacher preparation programs and school accountability, and a crackdown against for-profit colleges accused of defrauding their students — already appear to be in opponents’ sights.

Congressional Republicans have put two sets of Education Department regulations on their list of rules to undo in 2017, and Trump surrogates have been ­intensely critical of the agency’s Office for Civil Rights, which has fielded tens of thousands of discrimination complaints and has made headlines for pressing schools to accommodate transgender students and deal with campus sexual assault.

The fate of the civil rights division — whose efforts are as reversible as they are dramatic — is a top concern for many advocates for children who are minorities, immigrants or LGBT or come from poor families.

“We’ve got some tough times ahead, but we are up to it,” Marian Wright Edelman, founder of the Children’s Defense Fund and an education civil rights icon, told advocates and career Education Department employees at the department’s headquarters. “You might as well hunker down, do your crying at nights and on the weekends. We are not going backwards.”

Many conservatives welcome Trump’s promise to scale back federal intervention after spending the past eight years pushing back against what they said was Obama’s overreach into public schools. His efforts produced little in the way of improvements for children, they argue, pointing to stalled and in some cases sliding student achievement on national math and reading exams. High school graduation rates rose to record highs under Obama, but critics say that’s a squishy measure of improvement, since states set their own graduation requirements and they can change over time.

King’s predecessor, Arne Duncan, used billions of dollars in stimulus funding and the promise of relief from the most onerous provisions of the widely hated No Child Left Behind law to nudge states into adopting his preferred policies, including new teacher evaluations, new Common Core State Standards and new standardized tests.

Those efforts sparked a backlash not only from conservatives but also from teachers unions and parents, ultimately helping to persuade Congress to replace No Child Left Behind with a new law, the Every Student Succeeds Act, that set significant limits on the Education Department’s power.

King allowed that, with the benefit of hindsight, there are things that he would have done differently. But he said that the fight over federal authority is mostly an inside-the-Beltway debate “divorced from the substantive question of ‘what’s the work that we should be doing as adults on behalf of kids?’ ”

The Obama administration has been correct on those substantive questions, he said. And many ­Republicans agree with the need for stronger teacher evaluations and standards. It’s just that ­Republicans say that states should and will make those changes on their own, while the Obama administration says the federal government needs to be vigilant.

“States’ rights and civil rights have not generally traveled together in the history of the United States,” King said. “That’s not a partisan point, that’s a fact.”

To some on the left, this is the sad irony of the Obama administration’s legacy on education: In trying so hard to push states to do what they viewed as right, Obama officials undercut the federal government’s ability to do its most important work — protecting the rights of the most disadvantaged kids.

“If you say, as I do, that the federal government is a major source for equity in education,” said Richard Kahlenberg of the Century Foundation, the Education Department’s undermining of the federal role “is kind of a tragic legacy.”