> That being said, many strands of postmodernism in universities have come to teach that there is nothing outside of language itself (that's a common reading of Foucault and Derrida), so everything can be seen as a language or sign system. Want to change "reality" (as if there is such a thing!)? Just change the language.

> Another stand holds that there are only two really important groups: the powerful / powerless, which could also be seen as the "oppressors" and "oppressed."

Those aren't really separate stands, the latter is a consequence of the former: if language (or, rather, beliefs which is transmitted between people by language) is the defining factor in reality, then the ultimately meaningful differentiation between people is whether they are influential in shaping belief (powerful) or not (powerless).

It's also directly contrary to the central theme of Marxism, which makes the association of these particular postmodernist viewpoints with Marxism bizarre. (Certainly, there are people who moved from Marxism to this kind of postmodernism, just like there are people who have moved from Marxism to capitalism or from Marxism to democratic socialism or from Trotskyism to neoconservatism.