What arguments were used to justify the ideas of white superiority in the US during the Martin Luther King Jr. Era?

by LastPlacePodium

I am currently writing an analysis of MLK's "Letter from Birmingham Jail" for school. I am assuming that the subject of race was debated during that time period. But I can't find any examples of real world examples of arguments used by racist whites at that time to attempt to justify their views. Were they typically religious justifications? Were there any famous racist intellectuals/cultural leaders at the time?

georgiademocrat

This may sound obvious, but many of the “intellectual white supremacists” argued through the vacuum of states rights and property rights. Many focuses on this idea and argued that the federal government would be overstepping their boundary.