Interesting. Uploaded on: 2023-11-27. I wonder if that's actually a legal upload, though. Also seems to currently be available as a $3 rental on YouTube US in SD quality:
https://www.justwatch.com/us/movie/the-american-ruling-class
I did just find the DVD though:
https://kinolorber.com/product/the-american-ruling-class-dvd
Apparently home DVD and educational rights are split. Kino has the home rights. Educational rights are here:
https://www.bullfrogfilms.com/catalog/arc.html
This is the point at which I throw up my hands and download it from the Internet Archive.