The Golden Aspen (Populus tremuloides), also called the Quaking Aspen or the American Aspen, has a communal root system. This collective growth system serves as a nice allegory for the ideals of communism, so the leaf could be a great symbol for American communism.
Aesthetically, it’s a departure from the typical hammer and sickle or yellow star, which could be useful for propaganda. This is my tossed together proposed flag. Intentionally simple.
I think the background should be red. Or black, I’m a centrist moderate after all.