Here are key moments from Education Secretary Betsy DeVos's announcement Sept. 7 of changes to the process of investigating and prosecuting sexual assault at schools and universities. (The Washington Post)

The Trump administration on Friday withdrew Obama-era guidance on how colleges and universities should respond to sexual violence, giving schools flexibility to use a higher standard of evidence in judging cases and formally shifting the federal stance on what has become an explosive campus issue.

The action crystallized a pledge Education Secretary Betsy DeVos made on Sept. 7 to replace what she called a “failed system” of civil rights enforcement related to campus sexual assault. In her view, the government under President Barack Obama did not strike the right balance in protecting the rights of victims and the accused.

Under Obama, the Education Department’s Office for Civil Rights had declared in 2011 that schools should use a standard known as “preponderance of the evidence” when judging sexual violence cases arising under the anti-discrimination law known as Title IX.

Common in civil law, the preponderance standard calls for enough evidence to determine that something is more likely than not to be true. That is lower than the “clear and convincing evidence” standard that had been used at some schools.

Victim advocates viewed the 2011 letter as a milestone in efforts to get schools to address the long-standing problem of campus sexual assault, punish offenders and prevent violence. It also dovetailed with a high-profile campaign by the Obama White House to combat sexual violence.

The Office for Civil Rights is now declaring that schools may use either standard while the government begins a formal process to develop rules on the issue. How long that will take is not clear. An Education Department official said the administration does not want to rush.

Terry W. Hartle, senior vice president of the American Council on Education, which represents college and university presidents, said schools are likely to take a cautious approach while they await definitive rules. “Schools will respond conservatively to this,” he said. “Most of them will leave in place what doesn’t need to be changed.”

But Hartle added a caveat: “All institutions are going to need to look at their processes to make sure they’re not biased against the accused.”

The department’s interim guidance requires schools to address sexual misconduct that is “severe, persistent or pervasive,” and to conduct investigations in a fair, impartial and timely manner. Schools will be allowed to have informal resolution of cases through mediation, if appropriate and if all parties agree. Obama’s team did not favor mediation, declaring it inappropriate for dealing with sexual assault allegations.

“This interim guidance will help schools as they work to combat sexual misconduct and will treat all students fairly,” ­DeVos said in a statement. “Schools must continue to confront these horrific crimes and behaviors head-on. There will be no more sweeping them under the rug. But the process also must be fair and impartial, giving every­one more confidence in its outcomes.”

Catherine E. Lhamon, who was assistant education secretary for civil rights under Obama and now chairs the U.S. Commission on Civil Rights, denounced the action.

“The Trump administration’s new guidance is dangerously ­silent on critical parts of Title IX,” she said in a statement. “This backward step invites colleges to once again sweep sexual violence under the rug. Students deserve better, the law demands better, our college and university community must continue to commit to better, and we as a country must demand more from the U.S. Department of Education.”

Friday’s action formally withdrew the Civil Rights Office’s “Dear Colleague” letter of April 4, 2011, and a follow-up statement of “Questions and Answers” issued on April 29, 2014.

Laura L. Dunn, an attorney with SurvJustice, a Washington-based legal and policy advocacy group for survivors, said the department’s actions will allow colleges to give an unfair edge to the accused in sex discrimination cases. “This is simply unlawful, to flip a civil right on its head,” Dunn said in a statement. She said the department had acted beyond its authority.

Robert Shibley, executive director of the Foundation for Individual Rights in Education in Philadelphia, a group that opposed the Obama policy, praised the development. “It’s a great day for fundamental fairness on campus,” Shibley said. He called it a “necessary but not sufficient step,” acknowledging that colleges retain control over their internal misconduct rules and proceedings.

It is by no means certain whether, or how much, colleges will change their protocols.

Janet Napolitano, president of the University of California, told reporters Wednesday she does not expect the 10-campus UC system to drop the preponderance standard.

“UC’s pledge to protect our students and employees from sexual violence and sexual harassment remains unchanged,” Napolitano, who was homeland security secretary under Obama, said in a statement Friday.

The interim guidance could affect federal civil rights investigations at some colleges and universities. As of this month, the department reported that more than 250 schools faced inquiries related to their handling of sexual violence complaints. Those investigations are ongoing, officials said, but certain cases could be reevaluated if they are directly related to the 2011 guidance that has now been rescinded.