Be careful where you tread here. You must be careful to separate "communists" (people who believe in economic reorganization away from the power of capital) and "tankies" (those who support corrupt regimes that project the illusion of communism).
There are indeed quite a few communists and various other alt-camp political spectrum believers on here. They do have quite liberal beliefs but don't typically cause much of a fuss, because rational people can coexist with differing beliefs... and i dont mind them one bit. But the tankes, like lemmygrad, hexbear, etc, do stir up an anti-west "commie propaganda"fuss every chance they get, without being related to actual communism, especially if one mentions a hot button like Israel or Ukraine. And if you get into an argument with a tankie, they will just sling mud on you and call you a Nazi.
The cool part is, you can filter a lot of the chaff by just blocking the ugly instances from your user settings page (since Lemmy supports that now), blocking frequent flyers, and trimming/moving your subscribed community list to other, often smaller instances. A minimal amount of effort VASTLY increases the quality of content you'll see on lemmy.