The US Justice Department finally is confronting Harvard University and other elite colleges that blatantly discriminate against Asian-American applicants with a quota system.

To get into Harvard, students of Asian heritage have to score hundreds of points higher on competitive exams than non-Asians with similar or even inferior academic records.

That’s why the Trump administration’s Justice Department is demanding Harvard’s admissions records and launching an investigation. No surprise Harvard is stonewalling. It has plenty to hide.

Harvard’s quota system is a direct threat to the American dream for countless Asian families here in New York City and across the nation. Often new to the country and struggling economically, these parents make sacrifices and encourage their children to study diligently.

It pays off. Asian students make up 60 percent of the students in New York’s highly competitive specialized public high schools, like Stuyvesant and Bronx High School of Science.

But Harvard is shutting its door to many of them. As the number of Asian-American college applicants with top academic credentials has soared over the last two decades, Harvard has kept acceptances at around 20 percent of each entering class. Harvard doesn’t admit that, but the proof is in plain sight.

In 2014, Harvard was sued by Students for Fair Admissions, an advocacy group of mostly first generation Asian-Americans, including parents of high-school students striving to qualify for Ivy League admissions. Their lawsuit claims that the rigid racial make-up of every Harvard class — with consistent percentages of whites, Hispanics and blacks — is the result of an illegal quota system and insidious discrimination.

In states like California that bar affirmative action in public college admissions, the soaring number of college-age Asian-Americans has led to a rapid increase in their presence on competitive campuses. Asian-American students now win nearly half the places at California Institute of Technology, up from only a quarter in 1992. But not so at Harvard — proof, according to Students for Fair Admissions, of a secret quota.

The Students for Fair Admissions lawsuit also cites Harvard admissions officials stereotyping Asian applicants. One official described an applicant as “quiet, and of course, he wants to be a doctor.” Harvard seems to pigeonhole Asian students as math and science grinds who add little to campus life.

Harvard has spent millions of dollars on legal maneuvers and court filings, trying unsuccessfully to get the lawsuit dismissed and to shield the college’s “holistic” admissions process from scrutiny. But a federal judge is compelling the college to hand over six years of admissions records. Stuyvesant, Boston Latin, Thomas Jefferson High School for Science and Technology in Virginia and Monta Vista in California — all Harvard “feeder schools” — were also subpoenaed to provide information.

This lawsuit is expected to be tried in Boston late in 2018, but no doubt will end up at the US Supreme Court.

Don’t count on the high court to back up Harvard’s use of racial preferences to achieve campus diversity. Last year, the justices split 4-3, when they halfheartedly allowed the University of Texas at Austin to consider race as one of many factors contributing to student body diversity. Justice Anthony Kennedy, writing for the majority, struck an uncertain tone, suggesting the issue would need to be revisited, and Justice Samuel Alito specifically cited discrimination against Asian-American applicants as a problem.

Meanwhile, the Justice Department is pulling no punches. In response to a complaint from more than 60 Asian-American groups alleging discrimination at Harvard, civil-rights lawyers at Justice are demanding to see admissions records. So far Harvard has not produced a single document. The Justice Department has imposed a final deadline of Dec. 1 and is threatening to sue the university.

Harvard’s racial-quota system is indefensible. Fortunately, its days are numbered, because finally we have a Justice Department willing to fight for colorblind fairness in college admissions.

Betsy McCaughey is a senior fellow at the London Center for Policy Research.