The U.S. Supreme Court case Fortson, Secretary of State of Georgia, et al. v. Toombs et al., 1964 revolved around the constitutionality of a state law in Georgia that allowed for at-large voting to fill seats in multi-member districts when no candidate received a majority vote during primary elections. The plaintiffs argued this system diluted minority votes and violated the Equal Protection Clause of the Fourteenth Amendment by giving disproportionate influence to white voters over black voters due to racial bloc voting patterns prevalent at that time. However, the Supreme Court ruled against them stating there was insufficient evidence showing such an effect or intent behind this law's implementation. It held that as long as all qualified voters have an equal opportunity to participate in electoral processes and their votes are given equal weight once casted, it does not violate constitutional principles even if some groups find it harder than others to secure representation under these rules.

In the Supreme Court case Fortson v. Toombs, Justice Douglas dissented from the majority opinion. He argued that Georgia's county unit system was unconstitutional because it violated the principle of "one person, one vote." According to him, this system allowed rural counties with smaller populations to have a disproportionate influence on state elections compared to urban areas with larger populations. This resulted in unequal representation and undermined democratic principles by devaluing votes cast in more populous regions. Furthermore, he contended that even if there were legitimate reasons for maintaining such a system at its inception (such as ensuring adequate representation for rural interests), those reasons no longer held true due to significant demographic changes over time. Therefore, he believed that any deviation from strict population-based representation should be deemed unconstitutional unless compelling justification could be provided.