When President Donald Trump visits a school, it’s usually for a campaign rally, not a classroom tour. At his latest State of the Union address, he mentioned education just once. On Twitter, he has used the word “education” six times while in office, compared with 500 uses of the word “border.”

Education, it’s safe to say, is not his top priority.

Instead, Trump entrusts that realm to Education Secretary Betsy DeVos, who after two years has emerged as one of the most polarizing figures in his Cabinet yet also one of its most enduring members. While chiefs of a dozen other agencies have quit or been fired, DeVos has survived and shows no intention of leaving.

“Just because she’s been a lightning rod and been engaged in controversy doesn’t mean she’s not doing her job,” said Sen. Lamar Alexander, R-Tenn., chairman of the Senate Health, Education, Labor and Pensions Committee. “She’s come and she has stayed, which is more than you can say about some others in the Cabinet.”

Among DeVos’ supporters, there’s a belief that Trump’s distance from education is a blessing. While the White House focuses on issues such as immigration and the economy, DeVos has been free to continue her push for school choice, the topic that drew her into education and fueled her more than 30 years of advocacy.

In return, Trump gets an education leader who appeals both to school choice supporters and to evangelical Christians. DeVos, 61, who was raised in the Christian Reformed Church, is known for her devout faith and often weaves religion into her education speeches.

Despite her distance from Trump, she has a longtime friendship with Vice President Mike Pence, and has built other alliances across the administration, her aides say, including with Ivanka Trump, the president’s daughter and adviser, and her husband, Jared Kushner.

It also helps that, in a Cabinet plagued by scandal, DeVos has kept a clean ethical record. Unlike several of her peers who have faced inquiries over lavish travel taken at taxpayer expense, DeVos travels in a family plane and covers the cost herself. Every year, she distributes her $200,000 salary among different charities.

“Lots of people disagree with her, but not because she’s done the wrong thing,” said Nathan Bailey, her chief of staff. “She’s probably the person of the deepest personal integrity I’ve ever met in my life.”

DeVos has shied away from media attention, and her staff said she was unavailable to be interviewed for this story. She is scheduled to speak Monday to education journalists, her first appearance at a conference that has been a regular stopping point for her predecessors.

For an education secretary, DeVos has attracted a remarkable amount of vitriol. She’s reviled by teachers unions, who oppose her school choice policies and call her an enemy to public schools. She’s a common political target for Democrats, who have vilified her in campaign ads from Michigan to Texas.

Detractors portray her as an aloof billionaire with a poor grasp of education policy, an image that hasn’t been helped by occasional public gaffes.

At her 2017 confirmation hearing, for example, she appeared confused when asked about a federal law protecting students with disabilities. Later she was mocked after suggesting some schools might need guns for protection against grizzly bears.

Her aides say DeVos continues to receive support from Trump and has a good relationship with him. But behind the scenes, occasional conflicts with the White House have bubbled into public view, including during a March dispute over funding for the Special Olympics.

In private meetings, DeVos had objected to an administration proposal to eliminate money for the Special Olympics, a group she supports. But when the cut was kept in place in Trump’s 2020 budget proposal, DeVos fell in line and defended it in public, even though it drew intense criticism from Democrats.

As public outcry grew, however, Trump changed course and restored the money, saying, “I have overridden my people.” To some on Capitol Hill, it sounded like Trump was throwing DeVos under the bus even after she loyally defended a White House proposal.

“The president didn’t do her any favors by changing his mind on his own budget when the iron got hot,” said Alexander, education secretary in the early 1990s. “It’s not her budget, it’s the president’s budget, and everyone in the room knew it was never going to be adopted.”

DeVos aides say she didn’t take it as a slight. But at a Washington event the next day, when asked if she was glad to be secretary, DeVos said yes — “most days I am.”

Other conflicts with the White House have stayed quieter. DeVos disagreed with the administration’s early decision to revoke Obama-era guidance protecting transgender students, for example, and a recent executive order from Trump upholding free speech on college campuses. DeVos had previously spoken against a federal response to free speech disputes but stayed quiet on the issue when Trump issued his order.

Some who know DeVos are confounded by her persistence. She doesn’t need the money. She has no dream of higher office, they say. She could easily pack up and return to the comfort of her home.

“I have wondered why in the world she keeps doing this,” said Rev. Robert Sirico, a family friend and president of the conservative Acton Institute think tank. “It’s not for personal gain. It’s certainly not for personal aggrandizement.”

The answer he arrives at: “She believes the truth of what she professes,” he said. “It’s because she thinks this is going to benefit the kids in American schools.”

At times, rumors have swirled that DeVos would quit. As recently as November, after Democrats won control of the House, even some conservatives expected her to step down. But she dismissed the rumors, and if anything she has ramped up her work since then.

She recently started touring the country to promote her new school choice initiative, a proposed tax credit to support scholarships sending students to private schools and other education options. It’s meant to be a more politically viable option than her past school choice plans, which failed to gain traction even in her own party.

Win or lose, supporters say she has succeeded in widening the conversation about school choice, and has encouraged more states to consider it.

“I didn’t expect her to be anyplace further than she is right now,” said Rep. Tim Walberg, R-Mich., a friend of DeVos. “But she has put the dialogue out there, and it is causing us to talk about things that haven’t been on the docket for a number of years.”

Democrats, though, say DeVos is taking the country in the wrong direction. Her new plan has drawn wide pushback from Democrats, including Rep. Bobby Scott, D-Va., chairman of the House Education and Labor Committee.

“Her focus has been on voucher programs and school choice,” he said. “I think the focus ought to be on students being educated in public schools.”

Two other Democrats recently called on DeVos to resign, saying she has endangered students by rolling back Obama-era guidelines protecting transgender students, racial minorities and students who were cheated by for-profit colleges. Rep. Mark Pocan, D-Wis., wrote that DeVos should quit “before her actions wreak even more havoc than has already occurred.”

Her aides say she isn’t going anywhere.

“She doesn’t need this job, and I think that actually gives her some liberty to stay focused,” said Bailey, her chief of staff. “The noise that tends to distract and bog down people who are more focused on the politics of things, it doesn’t get to her.”