CAMBRIDGE, Mass. (AP) — The Supreme Court has agreed to review a challenge to the consideration of race in college admission decisions, often known as affirmative action. With three new conservative justices on the court since its last review, the practice may be facing its greatest threat yet.

The court said Monday it would consider a pair of lawsuits alleging that Harvard University and the University of North Carolina discriminate against Asian American applicants. The practice has been reviewed by the court several times over the past 40 years and has generally been upheld, but with limits.

A look at the case:

WHAT ARE RACE-CONSCIOUS ADMISSIONS POLICIES?

When colleges sort through their applicants deciding which ones to admit, some consider race along with grades and a host of other factors like athletics and community service. Some schools have used the practice for decades as a way to address racial discrimination against Black students and others who were long excluded from America's colleges. Today, supporters say it's an important tool that helps bring a diverse mix of students to campus, while opponents say it amounts to its own form of discrimination.

Most colleges don't disclose whether they consider race, but the practice is believed to be limited to a small fraction of schools. Some estimates put it at a few hundred of the nation's 6,000 colleges, mostly at more selective colleges.

Most states allow affirmative action but nine have outlawed it, including California, Florida and, most recently, Idaho, which banned it in 2020.

WHAT'S THE LATEST CHALLENGE?

The Supreme Court is taking up two lawsuits filed by Students for Fair Admissions, a Virginia-based group that says race should play no part in the admission process. The group is led by Edward Blum, a legal strategist who has spent years working to rid racial considerations from college admissions.

In its lawsuits, the group argues that Harvard and UNC intentionally discriminate against Asian American applicants. Examining six years of data at Harvard, the group found that Asian American applicants had the strongest academics but were admitted at the lowest rates compared to students of other races.

It also found that Harvard's admissions officers gave Asian Americans lower scores on a subjective "personal" rating designed to measure attributes such as likeability and kindness.

A federal judge in 2019 upheld Harvard's admissions practices, saying it was "not perfect" but passed constitutional muster. The judge said race-conscious practices always penalize groups that don't get an advantage, but they're justified "by the compelling interest in diversity" on college campuses.

An appeals court upheld the ruling in 2020.

The group brought similar claims against UNC, saying its process disadvantages white and Asian American students. A federal judge sided with the university last year.

In its appeal to the Supreme Court, the group asked the panel to review both cases and also to overturn the court's 2003 decision in Grutter v. Bollinger, which upheld admissions policies at the University of Michigan's law school. That decision cleared colleges to consider consider race if it's done in a "narrowly tailored" way to serve a "compelling interest."

The group's appeal argued that the Grutter decision "endorsed racial objectives that are amorphous and unmeasurable and thus incapable of narrow tailoring."

WHAT HAS THE SUPREME COURT SAID ABOUT AFFIRMATIVE ACTION?

Race-conscious policies have gone before the Supreme Court several times dating to the 1970s and have generally been upheld, with some limits.

Racial quotas that reserve a certain number of seats for minority students have been deemed unconstitutional, but the court has said colleges can consider race as long as it's one of many factors in the decision.

Students' race can be used as a "plus factor" to give them an edge, but it can't be the defining factor, the court has said. Schools must be able to show they consider race in a "narrowly tailored" way, and that there is no race-neutral approach that would meet the same objective of increasing student diversity.

The court last examined affirmative action in 2016, when it upheld the admissions process at the University of Texas. That suit, also orchestrated by Blum, was filed by a white Texan who was denied admission to the university.

WHAT ARE THE POLITICS?

The Trump administration sided with Blum in the Harvard case, saying in 2018 that the school's process "may be infected with racial bias." The administration also rescinded an Obama-era policy encouraging schools to consider race, and it filed its own lawsuit accusing Yale University of discriminating against Asian American and white applicants.

The Biden administration later dropped the Yale lawsuit and supported Harvard against Blum, urging the Supreme Court not to take up the case.

Meanwhile, the court has shifted further to the right, with three new conservative justices appointed by Trump.

WHAT IS THE POSSIBLE IMPACT?

Affirmative action backers hope the court leaves things as they are, giving colleges flexibility to consider race within certain bounds. Opponents hope for a sweeping decision that would remove race from the admission process entirely.

Eliminating the practice would send shockwaves across American higher education and leave many schools scrambling to find other ways to promote diversity. Some colleges say that, without considering race, they would expect to see a decrease in their Black student populations.

Opponents say ending affirmative action would make the process fairer, and some say colleges could preserve racial diversity by giving an advantage to low-income students.

Between both extremes are a wide range of possible options. The court could add further restrictions on the practice, for example, or it could raise the standard of proof colleges must meet to show they're within constitutional bounds.

WHAT ARE PEOPLE ARE SAYING?

Blum welcomed the court's announcement, saying he hopes the justices will end racial considerations at all colleges. In a statement, he added that Harvard and UNC have "have racially gerrymandered their freshman classes in order to achieve prescribed racial quotas."

Harvard President Lawrence Bacow vowed to defend the school's use of race as one of many factors, saying it "produces a more diverse student body which strengthens the learning environment for all."

Several groups representing students of color denounced the court's decision to get involved. NAACP Legal and Educational Defense Fund director Sherrilyn Ifill said it "threatens the nation's ideals of equality."

In a statement, she said holistic, race-conscious admissions processes "mitigate systemic barriers to educational opportunities faced by many Black students and other students of color, ensuring that all hard-working and qualified applicants receive due consideration."

Some other groups applauded the news. Mike Zhao, president of the Asian American Coalition for Education, said Americans should have equal opportunity to achieve success "through hard work, determination and initiative."

"It's time for the U.S. Supreme Court to step up to protect our constitutional rights," he said in a statement.