Final answer:
The Plessy v. Ferguson Supreme Court decision was problematic because it institutionalized racial segregation under the 'separate but equal' doctrine, misapplying the Fourteenth Amendment's equal protection clause and allowing states to maintain racial segregation laws. It remained legally acceptable until the Brown v. Board of Education decision in 1954, which began the dismantling of segregation.
Step-by-step explanation:
The Supreme Court's ruling in Plessy v. Ferguson was problematic because it was based on the belief that segregation was permissible as long as the facilities provided for both races were equal. This concept, known as 'separate but equal,' was upheld even though it institutionalized an entire system of racial discrimination. The decision gave constitutional protection to state laws establishing racial segregation, marking a grave misinterpretation of the equal protection clause of the Fourteenth Amendment.
The 1896 decision legitimized de jure segregation specifically with Louisiana's law requiring racial separation on trains and more broadly endorsed the notion that separation did not imply inequality or discrimination. This ruling stood until it was overturned by the landmark 1954 case, Brown v. Board of Education, which found that segregated schools were inherently unequal, thus beginning the process of dismantling the legal basis for racial segregation.
The sole dissenter in the Plessy v. Ferguson case, Supreme Court Justice John Marshall Harlan, opined that the Constitution should be colorblind and that all citizens were entitled to equal protection under the law, an ideal that would take decades to gain traction and fundamentally reshape American civil rights law.