I don't think that's true.
Marxism is no longer based on economics alone.
Now they attempt to brainwash the kids into thinking they're oppressed by a zillion different categories.
Fit vs. Fat
Abled vs. Disabled
English/French speaking vs. English
Straight vs. Gay
(Straight & Gay) vs. Transvestites
Legal Citizen vs. Illegal Alien
Male vs. Female
(Male & Female) vs Transvestites
Rich vs. Poor
Old vs. Young
Educated vs. Non-educated
Western vs. Non-Western
European vs. Non-European
Urban vs. Rural
White vs. People of Color
Immigrants labeled as "colonizer" vs. Indigenous
I pulled all those off of one of their high school indoctrination courses. There are more categories.
Then they do things to get kids to identify with as many categories as possible, such as claiming that if you're in one the oppressed categories, that means you are also a "disabled" person.
And where are they teaching this? In an ethics studies class, claiming that all those categories above are opposong "ethnicities"
So while you think your kids are learning about real ethnicities, they're teaching your kids these lies, and the kids don't know any better, because they don't know what is supposed to be taught in a real ethnics studies class. The kids don't realize these lies have nothing to do with ethnic studies
Now apply is to every course as much as possible in one form or another.