Thank you for writing this, Walter-helped me understand a situation that arose with my youngest and one of his teachers - who I now realize was guilty of abuse. Not sure what we called it then, but you've put the correct label on the situation.
5th grade
The school that (white) people with means find a reason to send their kids to another one in the district. Over 50% of the homes don't speak English, and most have very little money.
The teacher was berating one of the students for not bringing a notebook to class as was required and very clearly spelled out (in english) in the syllabus handed out earlier in the week.
My son kept trying to deflect her, but she kept coming back to "he doesn't have his notebook, therefore he's in big trouble".
5th grade
So of course (if you knew him) my son got up, walked over to the quietly weeping student and put his notebook on his desk, with a "problem solved" look on his face.
Yup - my son was written up for not having a notebook, which necessitated a trip to the office and a parent-teacher conference for not following the rules. The teacher still refused to back down and wanted him disciplined for "unruly behavior".
We bought him ice cream on the way home and let him know that we will always back him when he stands up to bullies (and abusers)