A year ago, affirmative action in higher education seemed safe for a generation, after Justice Anthony Kennedy blessed it in a landmark Supreme Court opinion. Now President Donald Trump’s Department of Justice is signaling that it plans to challenge the constitutionality of the practice in a way the federal government has never done before. And with Justice Neil Gorsuch in place and the possibility that Kennedy might retire in the next few years, the challenge could succeed. The legal reality is that higher ed affirmative action is now vulnerable.

The sense of security that followed Kennedy’s June 2016 opinion in Fisher v. Texas was a false one. Along with Kennedy’s liberal vote the same term in an important abortion case, Whole Women’s Health v. Hellerstedt, the affirmative-action decision seemed like Kennedy’s attempt to cement his liberal legacy. Given that most observers expected Democrat Hillary Clinton to be elected president, Kennedy’s legacy was expected to remain intact when she nominated successor justices to Antonin Scalia and eventually to Kennedy himself.

QuickTake Affirmative Action

In particular, Kennedy’s affirmative-action opinion embraced the theory that admissions officers at public universities may use diversity as their rationale to give several advantages to applicants of color. The idea goes all the way back to a solo concurring opinion by Justice Lewis Powell in a 1978 case called Regents of the University of California v. Bakke, which embraced Harvard University’s description of its admission practices at the time.

As interpreted by Justice Sandra Day O’Connor in a pair of 2003 cases involving the University of Michigan and by Kennedy last year, the diversity approach prohibits racial quotas. And it doesn’t allow universities to expressly give more points in an admissions system merely on the basis of race.

But diversity does permit admissions officers to make “holistic” judgments about applicants and curate a class that includes people from many different backgrounds. In practice, at the institutions that use the technique -- which is almost all major universities, whether state or private -- the racial balance ends up looking remarkably similar from year to year.

It was highly significant that Kennedy embraced the diversity rationale in 2016, because he had been a skeptic of affirmative action in the past, and had repeatedly voted to send the Texas case back to the lower courts, apparently trying to avoid issuing a definitive judgment. His opinion therefore seemed to settle the law, at least until the Supreme Court took on a different configuration.

Enter Trump and his attorney general, Jeff Sessions. According to an internal Justice Department document leaked to Charlie Savage of the New York Times, the department is looking for internal volunteers to work on an investigation and litigation of “intentional race-based discrimination in college and university admissions.” The investigation would be run out of the political part of the civil rights division, where Sessions’s policy team can keep an eye on it.

The memo shows that the Trump White House is coming after the diversity approach. There are at least two ways the administration can do it, not mutually exclusive.

The less radical line of attack would be to try to prove that, despite saying that they rely on the diversity approach, some universities are really using unlawful quotas. The first piece of evidence would undoubtedly be the similarity of the statistical numbers of racial minorities each year at many such institutions.

Another piece of statistical evidence would be systematic under-admission of some groups of students, such as Asian Americans. A lawsuit against Harvard University (my home institution) alleges that Asian American applicants are rejected disproportionally when measured by their grades and test scores -- and that Harvard’s “holistic,” diversity-based approach is a smokescreen for discrimination.

It’s notoriously hard to prove intentional discrimination by statistical evidence. The magic bullet would be internal documents showing that somewhere, some university is cheating by expressly giving points for race and setting quotas. It’s unlikely, but not impossible, that such evidence exists at some institution that has been sloppy in following the law.

The other route for the Department of Justice would be to start investigating for litigation now, and wait for Kennedy or Justices Ruth Bader Ginsburg or Stephen Breyer to retire before a case wends its way through the lower courts and ultimately to the Supreme Court. The goal would not be to ask Kennedy to reconsider his position, but to wait until there are five votes to overrule the Fisher case, or at least narrow it.

Either way, the Justice approach is a significant departure from past practice -- because for the most part, anti-affirmative-action litigation has always been a private affair. The named plaintiffs in such cases are typically candidates who say they were denied admission on the basis of race.

The federal government always has the opportunity to weigh in on such cases as a friend of the court. The George W. Bush administration, for example, asked the Supreme Court to treat the University of Michigan’s admissions practices as unconstitutional quotas in the course of the litigation that ended in 2003.

But that’s a far cry from the federal government leading the charge against affirmative action in higher ed. Here Trump and Sessions will be breaking new ground. It’s another reminder that, whatever limits Trump faces in building coalitions to pass legislation, there is plenty he can do solely in the executive sphere to affect the country’s future.

This column was provided by Bloomberg, and does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.