In the 2006 case Parents Involved in Community Schools v. Seattle School District No. 1, the U.S Supreme Court ruled that public schools cannot use race as a primary factor in assigning students to schools for purposes of achieving racial integration. The court held that while promoting diversity and avoiding racial isolation are compelling interests, they must be achieved by means other than an explicit racial classification system. In this case, two school districts had implemented plans which factored race into student assignment decisions with the aim of maintaining racially diverse schools. A group of parents sued on behalf of their children arguing these policies violated equal protection rights under the Fourteenth Amendment because it discriminated based on race. The court agreed and found such practices unconstitutional unless narrowly tailored to serve a compelling government interest - criteria these particular plans did not meet.

In the dissenting opinion for Parents Involved in Community Schools v. Seattle School District No. 1, Justice Breyer argued that the majority's decision was a significant departure from previous Court rulings on racial integration and diversity in schools. He contended that the school districts' plans were constitutionally permissible as they aimed to maintain racially diverse schools and prevent re-segregation, which aligns with precedent set by Brown v. Board of Education (1954). The voluntary measures taken by these districts did not impose burdens on any racial group but sought to include students of all races in each school proportionately reflecting community demographics. Furthermore, he criticized the majority for equating race-conscious student assignment policies intended to promote integration with those historical practices designed to enforce segregation - an analogy he found deeply flawed and misleading.