In the case of Spomer v. Littleton in 1973, African American residents and voters of Cairo, Illinois filed a lawsuit against Alexander County's State Attorney Robert G. Spomer for failing to protect their constitutional rights by not prosecuting white individuals who committed violent acts against them. The plaintiffs sought an injunction requiring him to prosecute these cases diligently and without racial bias. However, the Supreme Court ruled that federal courts could not mandate state prosecutors to initiate specific prosecutions because it would disrupt the balance between state and federal authority established by our Constitution’s system of dual sovereignty. The court also noted that there was no clear evidence showing that Spomer had intentionally failed to prosecute whites who assaulted blacks or violated their civil rights due to racial discrimination; thus, they couldn't prove he acted with discriminatory intent or purposefully denied equal protection under law based on race.

In the dissenting opinion for SPOMER v. Littleton, Justice Douglas argued that the majority's decision was a departure from established precedent regarding federal courts' ability to intervene in state proceedings. He contended that this case should have been treated as an exception to the general rule against such intervention due to its unique circumstances - namely, allegations of racially discriminatory prosecution practices by local officials. According to Douglas, these allegations were serious enough and sufficiently supported by evidence that they warranted immediate federal court attention rather than waiting for resolution through state channels. The justice also expressed concern about potential harm caused by delaying relief until after completion of potentially unjust prosecutions.