My opinions. Wikipedia will be more thorough and less biased, but you could easily look it up on Google or Wikipedia. You came here to garner opinion, so here is mine:
Every university in America has a group of Marxists among the faculty. Typically, they are in the English Dept. Typically, they have never known want
Marxism is a kind of criticism. Not criticism in the negative sense, but in the sense that it's a set of criteria by which you can analyze any text.
A text can be a movie, or a legal document, or a political manifesto.
Marxism is interested in power; who has it, how it is maintained. However, Marxist criticism seems to be bound to materialism such that it only makes
sense as a political philosophy if you have a materialist view of reality.