I guess what I'm getting at there is, content aside, Google has made a conscious decision to step in here and de-rank that website. We don't know what their motivations for that are because they haven't stated that they de-ranked Breitbart.

Sundar Pichai was asked during testimony if they censor websites and he said (wording might be a bit off) "only in cases where it's a legal requirement or a copyright issue". If Breitbart being de-ranked was one of those then I'm sure they would have let Breitbart know. But as far as I can tell it was a concerted effort to suppress that website in particular.

If you come across any data about other sites that are similarly affected I'd love to know!