I’m linking here to a brief but excellent AJ+ interview of Mike German, who infiltrated white supremacy groups as an FBI agent in the 1990’s.  To me, German appears to offer a nearly academic analysis of what such organizations actually are and how they appeal to people — but his explanations are easy for any layperson to understand.  He is also critical of both Obama and Trump.

He says some disconcerting things about why these groups are an increased threat in the America of 2017.