What about party members? When people join the party, are they taught Marxism-Leninism?
Wikipedia says 5.3 million people are party members, which is about 5.3% of the population, so if that’s true you’d think it would spread the ideology a bit.
Another question: when you say liberalism what do you mean? Is there political correctness and that weird American identity-politics stuff in Vietnam?
Check out Fearless Blood - it’s exactly about Chinese bandits in that era