The United States Constitution is said to be a "living document" in part because court interpretations change over time. What was a key aspect of Plessy v. Ferguson, a Supreme Court decision that was later overturned?

The key aspect of that sentence was to affirm the notion that racial segregation was not unconstitutional. The rule of Plessy v. Ferguson states that separated facilities for different racial groups (actually for whites and for blacks) don´t violate the US Constituion as far as they are equal , that is, they offer equal conditions. The initial complaint had to do with a public pool. The sentence was overturned by the 1954 Brown v. Board of Education regarding separate schools for black for white children; it held that even under equal conditions, segregated schools were unconstitutional.

Explanation:

i believe the answer is:

-   william jennings bryan is a democrat while mckinley was a republican

at that time, the segment of population that choose for democratic party were the voters with low economic background and vice versa

- william jennings has support of populists and wants to have inflation to farmers while mckinley has support of bankers and businessmen , doesn't want inflation

the fixed value of gold make the large business able to stack up their gold without   being worried that it would devaluated.

- william jennings supported the silver standard while mckinley supported the gold standard

according to jenning, using other metal beside gold could the poor people to have more purchasing power and them advance in the society.