The kind that thinks communism is the same as nazism and thinks communism is when the government does things.
I hate liberal brain worms.
They seriously do as much damage to the left as fascists by punching to the left and spreading capitalist anti-left propaganda. They overall weaken leftism and help fascism.
We need more left unity, folks. Fash ain't gonna bash themselves. 
Yeah, you got it. It just doesn't come up in real life much at all. Surprisingly it seems stuff that happened 100 years ago on another continent don't have much relevance to scattered socialists in America in 2023. The theory yeah that's still relevant, but the intricacies of what to denounce or who did what war crime? Dude we're trying to get 5 car wash employees to strike to get a $2 raise. Let's focus on tasks. There just aren't enough of us to bicker.
The most relevance it might have is when we're deciding what to put on signs at a protest. Should we use a sickle and hammer? Should we use a portrait of Lenin? Depends on why we're there and who we're dealing with.