Technically, this bunch was a group of "thinkers," though it's hard to compare their thought process to anyone in the Civil Rights Movement. It's a standing question how people can be so viciously racist and violent to people with a different skin color. Psychologists and sociologists have written about this subject for a long time.

They've got some good theories.

One very simple answer to the question of racism is that everybody likes to belong to something greater than themselves, and everybody likes to have power. For white people in the South, that power historically came from owning slaves. When they couldn't have slaves anymore, a lot of white people could still feel powerful by making African Americans unequal at every turn.

Racial hatred and intimidation has been embedded in American culture for so long that remnants of it are still hanging around despite changes in unjust laws (or maybe because of changes in unjust laws). And while the KKK isn't what it used to be, there are still people who actually spend whole evenings putting white sheets over their heads and burning giant crosses in the woods.

Don't they have anything more productive to do?