For Ms. Jones, they also reflect unfinished business. After she left the department, she joined the board of the American Academy for Liberal Education, the religious-school accreditor that prompted her resignation, where she railed against the Education Department’s accreditation process.

In the Trump administration, she has found exoneration. When the accreditation rule-making session ended, with negotiators reaching a rare consensus, in April she popped champagne in the negotiating room. She trumpeted that the rules cut down on “bureaucratic minutiae that distracts institutions from students.”

Consumer protection advocates see the rules as part of a larger plan to allow Ms. Jones’s allies in the for-profit industry to proliferate and operate with few guardrails. Some of the proposals reflect wish lists that for-profit and career schools have lobbied for in Congress. They throw a safety net to accreditors and programs that have struggled to meet departmental standards.

“The proposed regulations cut any serious oversight of colleges off at the knees,” said Clare McCann, the deputy director for federal policy at New America, a policy research group. “Bottom-feeder colleges will be able to keep enrolling students and pulling in taxpayer dollars for years, and it will be nearly impossible for the Education Department to take action against failing accreditors.”

Some higher education experts have been supportive but cautious. Terry Hartle, a vice president at the American Council on Education, an association representing more than 1,700 colleges and universities and related organizations, said the accreditation rules were “important, incremental movements” that have been long desired by a range of institutions. He served on the committee of department-appointed negotiators, including department officials and consumer protection and higher education representatives, and said the rules would allow high-quality institutions to experiment in new ways.

Mr. Hartle, who has known Ms. Jones for more than a decade, said he believed allegations that the rules were designed to benefit flailing for-profits was an “easy answer.” “Diane is extremely knowledgeable and she’s always been a professional,” he said.

What opponents and proponents can agree on is that none of the changes are as contentious as Ms. Jones herself.