Considering the rapid growth of charter schools, it’s important for the public conversations about school choice to distinguish fact from rhetoric and sloganeering. For instance, proponents of charter schools, such as Success Academy CEO Eva Moskowitz, claim charter schools advance racial integration of children and give parents options for “voluntary integration.” Is this true?

More than sixty years ago, the U.S. Supreme Court ruled unanimously in the Brown vs. Board of Education decision to abolish the separate but equal legal doctrine and Jim Crow segregation by race.

The ruling was a watershed moment for the United States because it contradicted the prevailing wisdom and popular opinion in many quarters. In sum, the Supreme Court sought to change an inherently racist society by ruling that segregation in schools violated students’ right to equal protection of the laws guaranteed by the Fourteenth Amendment of the U.S. Constitution.

Members of the civil rights community have expressed that charters have turned back the clock on segregation to pre-Brown levels. At the 2017 NAACP national convention, more than 2,000 delegates passed a new resolution entitled Public and Charter Schools Fulfilling the Promise of Brown v. Board that decries the segregation of African American students into under-resourced public schools and charters. The intensification of segregation in charters is especially important for the African American community because a new report by the NAACP’s Task Force on Quality Education found that one in eight African American students in the United States now attends a charter school.

Even though the popularity of charter schools has plummeted, the rise in the number of charters has been particularly rapid during the past ten years. Many states have lifted caps on the number of charter schools contained within the original state legislation, owing in part to millions of dollars in financial incentives created by federal grant programs. Funding encouraging charter growth has also poured in from state grant programs and funding from private foundations, especially the Walton Family Foundation (of Walmart fame) and the Bill and Melinda Gates Foundation.

The predominance of peer-reviewed research examining national and local data on the segregation of students in charter schools over the past ten years has demonstrated that school choice is exacerbating existing patterns of segregation. The research has actually shown this for about two decades. For example, using three national data sets, one research study found that charter schools are “more racially isolated than traditional public schools in virtually every state and large metropolitan area in the nation.” What this means in practice is that in schools where white students are overrepresented, white students have little exposure to minority students.

Research conducted by Vanderbilt University and Mathematica argued that charters are not “creating greater segregation,” but a careful reading of this study reveals that in the majority of states examined, white and African American students were more likely to choose even more homogenous charter schools.

Thus, one of the big problems with school choice is the peer-reviewed research demonstrating the finding that “Parents choose to leave more racially integrated district schools to attend more racially segregated charter schools.” Peer-reviewed research has also demonstrated that the choice of African American and white families for schools with homogenous racial compositions “helps to explain why there are so few racially balanced charter schools.”

The same study found that choice was also bad for achievement on average as, “the relatively large negative effects of charter schools on the achievement of African America students is driven by students who transfer into charter schools that are more racially isolated than the schools they have left.”

In contravention of Brown, charters are influencing and intensifying racial segregation across the nation. After several decades, the promise of charter schools to foster integration and a less balkanized society is clearly not being realized.