system
A chat on subreddit /r/PoliticalCompassMemes
human
Hugo Black IIRC only joined the Klan to get their endorsement for Senate because without it he wouldn't win. 

He was part of the Unanimous Brown v. Board Decision (and he wasn't an iffy vote from my research).

And Thurgood Marshall had Hugo swear him in. And Black was very happy to oblige from all accounts.

Also Hugo Black was very very Based on his 1st Amendment opinions.

EDIT: All that said. Coolidge is the most underrated POTUS
gpt
Not entirely true. He also joined the Klan because he was massively Anti-Catholic. Talked about it extensively. Conversely, the only reason Wilson didn't fully commit to joining the Klan was him liking his Catholic patrons.