U.S. Secretary of Education Betsy DeVos has long condemned what she calls “the overreach of the federal government in education.” She’s funded escape hatches out of public education, including private schools and home schooling, neither of which is under a federal mandate to test their students each year.

So why is DeVos insisting that states, including Georgia, give their students high-stakes tests amid a devastating pandemic that shuttered classrooms for months?

Because it serves her overarching goal of destabilizing public education in America, according to the authors of a new book, “A Wolf at the Schoolhouse Door: The Dismantling of Public Education and the Future of School,” due out Nov. 17. A major Republican donor and ardent school choice advocate in her home state of Michigan before joining the Trump White House in 2017, DeVos has styled herself as an adversary of public education rather than an ally.

“She spent 20 years saying the federal government should keep its hands off schools and mind its own business,” said co-author and education historian Jack Schneider in a telephone interview from Massachusetts. “Yet, here she is threatening states that, if they don’t give the tests required by federal law, there are going to be serious consequences. People are saying she is hypocritical because she is insisting on something she doesn’t believe in, but she feels the end justifies the means. She has one aim — turn public education upside down and shake as many families out as she can into a private system.”

The book delves into the political alliances and business interests that have pumped new energy and life into conservative policy ideas, including vouchers, long rebuffed by voters. Using the appealing language of “customizing” and “personalizing” learning, DeVos has become the face of a movement that echoes the efforts in the South to resist integration and essentially seeks to dismantle American public education, an institution begun nearly two centuries ago, and, while imperfect, still an ideal worth defending, said Schneider.

Co-hosts of the popular education podcast “Have You Heard,” Schneider and co-author Jennifer Berkshire contend that DeVos, often written off by critics as a lightweight, has deftly advanced the privatization of public education and enabled states to pass voucher programs, typically repackaged with more benign names such as educational scholarships or savings accounts.

“She is providing the vision and we are seeing that vision playing out at the state level,” said Berkshire, a longtime writer and commentator on education issues.

In their book, Schneider and Berkshire fault Republican leadership going back decades for a shift to elevating the private good over the public, but they don’t spare Democrats. They contend centrist Democrats and conservative Republicans established a treaty of sorts where each set aside their more extremist positions for a reform agenda that led to charter schools, Common Core State Standards, accountability and relentless testing.

“But Betsy DeVos has no interest in that treaty,” said Schneider, explaining that the education secretary is not abiding by the tacit agreement to stop the choice train at charter schools. DeVos wants to replace public schools with private ones, he said. From her early days in office, DeVos made a point to visit private schools that receive tax dollars.

At the same time that DeVos champions schools that spurn standardized exams, DeVos is weaponizing tests to demonize public schools as failing, according to Schneider, who teaches at the University of Massachusetts Lowell and wrote the 2017 book “Beyond Test Scores: A Better Way to Measure School Quality.”

The authors again fault both political parties for the hyper focus on testing, noting the Obama administration continued to emphasize test scores even as research piled up showing high test scores reveal more about the socioeconomic status of the students than the quality of the school. (It has never surprised educators that top marks in school ratings based on test performance go to the wealthiest, whitest schools.)

“Both centrist Democrats and conservative Republicans have convinced the American public that test scores are an indicator of school quality,” said Schneider. “That is not to deny there are bad schools out there, but the vast majority — if you ask the people who know them best — are not bad schools and do not require dramatic intervention.”

Berkshire believes DeVos' hostility toward public schools could backfire in suburban counties, including those in metro Atlanta, where parents love their schools. And that could come to a head when parents realize their public schools are losing funding, while DeVos busily finds more ways to divert public money to private causes, including her new program of micro grants to parents who home-school, she said.

“We are going to see these things get a lot uglier because of the budget crisis. At a certain point, these privatization programs will mean real pain is being inflicted on neighborhood schools,” said Berkshire in a phone interview from her home in Massachusetts.

Public schools are so focused on the pandemic and the challenges of reopening that they’ve yet to confront the looming fiscal cliff. While schools now worry about frustrated teachers quitting, Berkshire said mass layoffs may be around the corner when state legislatures confront shortfalls.

Berkshire and Schneider view their book as a rallying cry to preserve public education and to redouble efforts to force it to live up to its founding ideals. They contend conservatives and neoliberals have presented people with a false choice between a flawed public education system and a more privatized one.

“The answer to the flaws in the existing system is not privatization,” said Schneider, “but to make the current system more public by ensuring every school has adequate funding, ensuring all of our schools are racially integrated, that all schools have teacher capacity, the curricula capacity and any other necessary capacity to challenge kids and deliver a rich and balanced education.”