In the case of Barbara J. Norman, et al. v. Dorothy Reed, et al., 1991, the U.S Supreme Court dealt with a dispute over voting rights in Mississippi's Noxubee County School Board elections. The plaintiffs argued that an at-large voting system diluted African-American votes and violated Section 2 of the Voting Rights Act of 1965 by denying them equal opportunity to participate in political processes and elect representatives of their choice. However, the defendants contended that racially polarized voting was not sufficient evidence to prove vote dilution under Section 2 unless it could be shown that white voters voted sufficiently as a bloc usually to defeat minority-preferred candidates. The Supreme Court ruled against this argument stating that proof of racial polarization is only one factor among many which courts must consider when determining whether minorities have less opportunity than others to participate in electoral processes under Section 2; other factors include history of discrimination, socioeconomic disparities affecting opportunities for political participation etc.

In the dissenting opinion for Barbara J. Norman, et al. v. Dorothy Reed, et al., Justice Marshall argued that the majority's decision to uphold a Michigan law prohibiting school districts from using race as a factor in student assignments was fundamentally flawed and inconsistent with previous Supreme Court rulings on equal protection under the Fourteenth Amendment. He contended that this ruling ignored past precedents which allowed for consideration of race in certain circumstances to remedy historical racial discrimination or segregation issues within public schools. Furthermore, he criticized the majority's interpretation of "equal protection" by arguing it should not be used to prevent measures aimed at achieving actual equality rather than merely formal equality before the law.