Final answer:
The Warren Court's decision in Brown v. Board of Education represents how ideological shifts in the Supreme Court can lead to the overturning of an existing precedent, in this case, overruling of Plessy v. Ferguson's 'separate but equal' doctrine.
Step-by-step explanation:
The Warren Court's ruling in Brown v. Board of Education (1954) illustrates the aspect of Supreme Court decisions that Ideological changes in the composition of the Supreme Court can result in the rejection of an existing precedent. This case overturned the precedent set by Plessy v. Ferguson in 1896, which upheld the constitutionality of 'separate but equal' facilities and thus segregation. Instead, the Court unanimously concluded that separate educational facilities are inherently unequal, thus violating the Equal Protection Clause of the Fourteenth Amendment. The decision marked a significant turn in the judicial approach to civil rights and set a new precedent against racial segregation in public schools.