I don't even know if this is a true quote, however the actual sentiment of this quote is 100% true. The aggression of many modern "communists" in regards to those who are politically backward or otherwise think differently is horrific and originates in CIA-funded radical liberal movements and not actual Marxist-Leninist-(Maoist) thought.

It is a real quote and was also included in the Little Red Book
https://www.marxists.org/reference/archive/mao/works/red-book/ch28.htm