It didn't and it did. Just because the case happened in 1954 doesn't mean that schools ended segregation, as a matter of fact it lasted for almost a decade more, if not longer because schools would still refuse to obey. Southern communities were especially supportive of segregation, and even when the civil rights acts were implemented they still didn't support them and they didn't want to be around African-Americans only it had to be hidden. On the other hand, when a Supreme Court makes a decision it does sway people to support it. That is because there is an idea of everyone being equal in the eyes of law and the supreme court is the judge on what is lawful and what isn't based on the constitution. Since there's no greater legal act than the constitution, when the supreme court makes a decision it means that the decision fits the constitution and for many Americans the constitution is almost a holy document that guides their lives. A negative externality can be for example the rise of extremism. During the reconstruction period Ku Klux Klan rose as a negative externality of the era. During the civil acts era they grew stronger again because racist people were enraged by things like desegregation.
Not sure what the options are but there was a huge wave of immigration during that era.
The cause for the scandal was the discovery of bribery in the cabinet and the government regarding oil trade. One effect was that it proved that cabinet members are not all powerful and can be arrested and indicted just like anyone. Another effect was the Supreme Court's ruling in McGrain v. Daugherty which explicitly established that Congress had the power to compel testimony. A third effect was that the government was given back the oil fields that were leased and they stayed in US ownership until 2015 when it was legally sold.