May 17 marks the 65th anniversary of the Supreme Court’s ruling in Brown vs. Board of Education, which determined that segregating schools on the basis of race was “inherently unequal” and thus, unconstitutional.

But a new report finds that decades after that historic ruling, the phasing out of older programs to foster integration and a lack of new policies to take their place has left America’s schools increasingly segregated, especially for black and Latino students.

The report, released Friday by UCLA and Penn State, looked at federal student enrollment data and other research on school segregation. It found that students across America are increasingly attending racially isolated schools, with black and Latino students in particular attending schools that are predominantly nonwhite.

White students, meanwhile, are attending schools that are less white than they were in the 1950s and 1960s, but these schools still have far more white students than their share of the student of the actual student population.

“Since 1988, the share of intensely segregated minority schools—schools that enroll 90-100% non-white students, has more than tripled,” the report authors note.

The research suggests that efforts to desegregate schools have been undermined by a series of factors, including most notably, residential segregation.

As a result, the gap between black and Latino students and their white peers is growing wider, creating schools that are not only racially segregated, but economically segregated. Students attending predominantly black and Latino schools have less access to beneficial programs than their peers, the study found.

“As we mark [its] 65th anniversary, the promise of Brown appears a distant vision in our dangerously polarized society,” Gary Orfield, co-director of the UCLA Civil Rights Project and one of the report’s authors, said in a press release. “We have to do more.”

Much of the progress of the Brown ruling has been rolled back in the past three decades

The Brown case focused on states that that intentionally discriminated against black students, many (but not all) of which were in states that had also employed Jim Crow laws. And while that called attention to the most egregious offenders, it also allowed school segregation to continue in other areas beyond the South.

This was further compounded by a 1974 Supreme Court ruling in Milliken v. Bradley, which determined that districts that had segregated schools but did not intentionally separate students by race could not be forced into desegregation plans.

These decisions, and the fact that desegregation enforcement largely stopped in the 1990s thanks to Supreme Court rulings that integration plans weren’t supposed to be enforced indefinitely, produced a situation in which white and black students largely continue to attend different schools, often with widely varying access to resources.

But a major difference now is that further demographic changes in the US have also changed what America’s student body looks like, meaning that the school segregation is no longer a white/black issue, but one that includes other racial groups.

Here’s how the report describes the issue:

Although white students still comprise the largest racial group in our nation’s schools (23.9 million white students), after nearly a half-century of decline in the percentage of the overall enrollment, it is notable that white students no longer account for the majority of public school students (48.4%) in the United States. This is not because of a significant growth of the share of private schools but an impact of birth rates and immigration changes. The Latino share of enrollment has been growing tremendously such that more than half of the students of color in the United States identify as Latino (13 million students). Black students account for the third largest racial group (7.5 million) followed by Asian students, multiracial students, and American Indian students. This is a multiracial reality quite different from those existing at the time of the Brown decision.

So when we talk about school diversity in 2019, we are discussing a student body that looks far different than what it did in 1954. Yet the demographic makeup of our schools doesn’t fully reflect that new reality.

Instead, the report notes that it is common for black and Latino students to be largely concentrated in schools together, while white students, and to a lesser degree Asian American students, attend schools with larger white populations.

And this sort of segregation is not just about race: The report finds that black and Latino students are also more likely to struggle with what it calls the “cost of double segregation of race and poverty,” with students from these groups being disproportionately likely to live in lower-income households and attend schools with fewer resources.

White and Asian American students, meanwhile, are more likely to attend more affluent schools with more resources.

The report argues that increasing school integration is absolutely necessary

The UCLA report acknowledges that there are some nuances it doesn’t fully dig into. For one, while the report looks at four main racial categories of students: white, black, Latino, and Asian American, it doesn’t really grapple with the varying subgroups within these communities, particularly when it comes to the diversity of Latino and Asian American populations.

It’s possible that a closer look into these distinctions might reveal differences. The data, for example, might find that there are certain Asian communities more likely to attend schools that are predominantly black and Latino.

But even with this data missing, the report does paint a convincing picture of the ways that school segregation remains an issue across the country. The report notes that the states where black students are most likely to attend intensely segregated schools include places like New York, California, Maryland, and Illinois. The states where Latino students are most likely to attend racially segregated schools include California, New York, Texas, and New Jersey.

And while some high-profile cases, like the ongoing battle over admission into New York City’s selective high schools, highlight the fact that school segregation remains a serious problem in urban areas, the report notes that school segregation has also become a rapidly intensifying problem in suburbs where there was never an explicit mandate to not segregate.

As more people of color find themselves living in these areas, suburban schools are seeing white families move away, demand new zoning, or even attempt to create new predominantly white school districts. This has all been in motion for decades, and underscores the fact that school segregation is largely influenced by segregation in other areas of society, including most notably residential segregation.

The report authors write that they are concerned that the increasing isolation of people to certain schools and communities will negatively affect how students learn and their later lives, a concern that is supported by a growing body of research that has shown that the quality of public education has a serious impact on a child’s future.

There’s an argument that rather than focus entirely on racially integrating schools, there should be more schools focused on exclusively serving students of color, or that low performing schools should be given more support and resources.

The UCLA report focuses its recommendations on integration, including training teachers and school officials to better work with diverse student bodies, increasing the number of teachers and faculty from different racial backgrounds, and using a more expansive understanding of diversity that takes into account not just race, but how that intersects with language and economic differences. And it also argues that addressing school integration must become a more important priority for lawmakers and local communities.

“School segregation is not simply an educational issue that stands out in certain communities, or regions, but an imminent social issue that seriously threatens the cohesiveness of our nation,” Jongyeon Ee, an assistant professor at Loyola Marymount University in Los Angeles and an author of the report, said in a statement. “Segregation exacerbates our differences, fueling division and tension across our schools, communities and nation.”