@orekix Yeah, I don't think they were THAT effective with their efforts (same with western propaganda). I'm not sure how would you even measure it.
Lot of western leftist became quite disillusioned with it in the 1930's after information about the purges etc came out.
I remember reading some text from the US Communist party from the 1920's to use "the struggle of the negro" to strengthen their position, but I can't find it. Do you know about something like that or am I having a stroke?
@orekix Funny thing about this pamphlet is that the capitalists also improved the life of "the negro"
https://fee.org/articles/when-sears-used-the-market-to-combat-jim-crow/