Education Secretary Betsy DeVos. (Pablo Martinez Monsivais/AP)

A NEW report by the Government Accountability Office showing the role that racial bias plays in school discipline could not have come at a more critical time. Education Secretary Betsy DeVos is mulling whether to roll back Obama-era policies aimed at curbing racial disparities in discipline. The stark findings of this report should make Ms. DeVos’s decision easy, assuming of course she pays attention to the facts rather than listening to the ideologues pushing for repeal.

Black students, according to the report released this week by Congress’s nonpartisan watchdog agency, are more often disciplined in school and receive harsher punishments than white students for comparable offenses. Starting as early as preschool, black students experience the brunt of discipline from in-school suspensions to expulsions and school-related arrests. Young black males were most affected, but the pattern of unequal treatment extended to young black females. Particularly hard hit were black students with disabilities.

In what was seen as a groundbreaking finding, GAO researchers determined that the disparities could not be explained by poverty levels. Black students were suspended more often than their white peers regardless of the income level of schools studied. “There’s a racial discrimination problem, and that can no longer be disputed,” Daniel J. Losen, of the University of California at Los Angeles’s Civil Rights Project, told the New York Times.

The report was made public as Ms. DeVos met privately with supporters and opponents of a “Dear Colleague” letter issued in 2014 by the Obama administration urging schools to examine disproportionate discipline rates for black students and making clear there could be violations of federal civil rights laws for which schools could be held accountable. Critics of the guidance have claimed that schools have become less safe, with administrators feeling their hands are tied and that they are not able to impose needed discipline. Some even tried to link the guidance to the systemic failures that led to the Parkland , Fla., school shooting.

But, as the report makes clear, school suspensions began to fall the year before the guidance was issued, and no new mandates were imposed by the federal government. School officials have broad discretion in how they discipline students. Serious offenses, such as those concerning weapons or violence, do result in a student being removed from a school. But there are alternative, more effective ways to improve the behavior of students who act out or talk back or run in the hallway.

That there should be one standard that treats black and white students the same should be a no-brainer. Ms. DeVos should stop wasting time on whether to rescind this worthy guidance; indeed, in the wake of this report, she should affirm it. If she wants to help schools improve their approach to discipline, she should listen to the educators who told researchers that their biggest problem is a lack of resources to deal with the mental-health issues experienced by many of their students.