The US Supreme Court will hear oral arguments next week in two cases that could change the landscape of higher education in the country. The eventual outcomes will determine whether Harvard University in Cambridge, Massachusetts, and the University of North Carolina (UNC) at Chapel Hill are allowed to use race as a factor in deciding which students they admit.

But beyond that, the court’s decisions could mean that academic institutions across the United States will no longer be allowed to use ‘affirmative action’ policies to shape their student bodies.

Research has shown that without affirmative action, some universities – particularly top-tier institutions that enrol only a small fraction of applicants – will struggle to admit students from a wide variety of backgrounds.

“This will have ripple effects regarding who’s not able to have a seat at the table and enter certain professions,” says Julie Park, a researcher at the University of Maryland in College Park whose work focuses on racial equality in higher education.

Both cases have been spearheaded by activist Edward Blum, who created Students for Fair Admissions (SFFA), an organisation that represents “more than 20,000 students, parents and others who believe that racial classifications and preferences in college admissions are unfair”.

As the plaintiff in both cases, SFFA argues that, by considering race in their admissions, Harvard and UNC-Chapel Hill are discriminating against certain applicants, such as Asian American people. This, the group says, violates a clause in the Fourteenth Amendment of the US Constitution prohibiting states from denying anyone equal protection of the law, as well as the Civil Rights Act of 1964.

Harvard and UNC-Chapel Hill, however, argue that affirmative action has helped them to even out the playing field for Black and Hispanic students who have not had the same educational opportunities as others because of systemic racism in the United States.

The lawsuits aim to overturn a decision that the Supreme Court made about a case in 2003. In Grutter v. Bollinger, a white woman named Barbara Grutter alleged that she had been rejected from the University of Michigan Law School in Ann Arbor because of the institution’s use of race as a factor in its admissions decisions. She argued that the practice violated the Fourteenth Amendment and a section of the Civil Rights Act of 1964 that prohibits racial discrimination by any programmes that receive federal financial assistance. The university is a public institution and receives such funding.

In this instance, the court decided that the law school was allowed to consider the race of individual applicants, so long as it was done in a ‘holistic’ way — meaning that race is one factor among many that are considered. The justices also ruled that it is constitutional to consider race as part of a university’s effort to achieve more diversity on campus.

Blum has previously tried and failed, to block a university from using race-conscious admissions in the Supreme Court. But given the new make-up of the court – former US president Donald Trump appointed three justices, giving the bench a 6-3 conservative majority – he and SFFA are trying again, and looking to upend the entire precedent.

Both Harvard and UNC-Chapel Hill use the ‘holistic’ race-based approach to admissions, which SFFA contests. Grutter v. Bollinger “was wrong the day it was decided” and “has spawned significant negative consequences”, states the SFFA’s court filing.

Specifically, the group argues that race-conscious admissions at Harvard discriminate against Asian Americans, and at UNC-Chapel Hill, against both white and Asian American applicants, by unfairly favouring some students of colour, including Black and Hispanic applicants.

In many states, some percentage of public and private universities use affirmative action in admissions. But eight states – Arizona, California, Florida, Michigan, Nebraska, New Hampshire, Oklahoma and Washington – currently ban public universities from considering the race of their applicants.

Most US colleges don’t have to worry unduly about affirmative action, however, because they admit more than two-thirds of applicants, according to a 2019 study by the Pew Research Center, a think tank based in Washington DC.

The debates about affirmative action centre around a small number of ‘elite’ institutions with low acceptance rates, says Alvin Tillery, Jr, director of the Center for the Study of Diversity and Democracy at Northwestern University in Evanston, Illinois. Many of these are private universities, including Harvard, that have implemented their own voluntary affirmative-action policies.

The part that affirmative action has played in increasing diversity in higher education became clear after states such as California and Michigan banned race-conscious admissions at public institutions. These actions led to persistent declines in the enrolment of people from under-represented minority groups at the states’ flagship public universities, according to a 2020 study.

In a brief filed with the Supreme Court, lawyers for the University of Michigan stated that the enrolment of Black undergraduate students dropped from 7 per cent in 2006 to 4 per cent in 2021, even though the proportion of college-age people in Michigan who are Black rose from 16 per cent to 19 per cent.

And graduate students were affected, too. For instance, at medical schools in California, Florida, Michigan, Nebraska, Texas and Washington, affirmative-action bans led to about a 17 per cent decline in historically under-represented students of colour enrolling, according to a 2015 study.

Affirmative action isn’t perfect, Park says, “but it’s an essential tool in order to be able to recruit and enrol a more racially diverse group of students”.

Many universities agree. Fifteen institutions – including Brown University in Providence, Rhode Island, Duke University in Durham, North Carolina, and the University of Pennsylvania in Philadelphia – put forwards an amicus, or ‘friend of the court’, brief to the Supreme Court in support of affirmative action.

The American Council on Education sent a similar brief along with 39 other higher-education associations. They state that if race were to be excluded from admissions decisions, the experiences of Black Americans and other students of colour in the United States would be largely ignored. They also note that higher diversity facilitates varied interactions among students and prepares them for a diverse workforce.

The court does not have to consider the evidence presented in such briefs, but sometimes does.

This is one of the biggest cases to come before the heavily conservative court since it overturned decades of precedent by reversing Roe v. Wade, which had protected the right to an abortion. Having seen the outcome in that situation, many experts think that affirmative action in university admissions will come to a swift end.

The right-leaning justices seem willing to overrule established precedent, says Kimberly West-Faulcon, a legal specialist at Loyola Law School in Los Angeles, California. SFFA and its supporters are counting on that; decades ago, the Supreme Court ruled that a holistic approach to admissions that includes race is not unconstitutional. SFFA’s supporters, including 81 Republican lawmakers, filed their own amicus brief to the court arguing that race-conscious admissions “are untrue to the Constitution’s guarantee of equality under law”.

Daniel Ho, a legal specialist and political scientist at Stanford Law School in California, agrees that the court will probably rule in favour of SFFA.

The Civil Rights Act of 1964 was meant to protect historically marginalised groups, but that conception has been difficult to maintain, he says. Instead, SFFA is using it to protect ‘colour blind’ admissions. A decision on the cases is expected by next summer in the United States.

• A Nature report