I define Marxism broadly as the initial poisoning of the left-leaning mind with the concept of the ubiquitous class struggle. It has mutated into a belief system under which there is always an oppressing class and an oppressed class. It can be the landed gentry (oppressors) vs. the commoners (oppressed), capital (oppressors) vs. labor (oppressed), racial majority (oppressors) vs. racial minority (oppressed). But at its core, it is unable to view the current state of the world, or any subdivision thereof, in terms other than oppressed and oppressor, whether any reasonable person would agree or not. And, as can be seen with all Marxists (operating under there many self-ascribed labels), the only cure is revolution and purification. Of course, for those of us with a passing grasp of recent history, its quite clear that both of those will lead to mass violence and death. See also, the Bolshevik Revolution and its ensuing horrors, Mao's revolutions and their ensuing horrors, the Cuban revolution and its continued mass oppression, the French Revolution and all of its violent insanity, etc. etc.
> And everything is politics
And thus we arrive at Postmodernism. Postmodernism introduces the belief that everything is relative and everything is a construct. There is no base reality, no ground truth–or if there is, we can dismiss it as irrelevant given the all powerful constructs and systems of human life. Thus one can make arguments like, "Everything is always politics" and use such asinine premises as the basis of injecting noxious politics into every facet of our lives. Once again contravening the majority of people's lived experiences and desires.