Recently, I spent some time trying to understand so-called "Postmodernism." While many argue that Postmodernism is incapable of definition, that's only because the word "Postmodernism" itself became a pejorative term applied to anything viewed as contrary to conventional wisdom. If Marx were alive in the "Postmodern" era, he would have been falsely accused of being a Postmodernist.
Postmodernism is not a regime of word games, as some people seem to convince themselves it is. Rather, at the heart of Postmodernism lies the realization that our words ultimately fail us because the same words mean something different to different people. This is not to say that reality is subjective so much as it is to recognize that our ability to communicate objectively is hampered by the mismatch in understanding between the speaker and the listener. This kind of observation is often reduced to a kind of absurd abstraction that reality is somehow "linguistic," but, frankly, that is pure bullshit peddled either by ignorant assholes or opportunistic assholes.
What Postmodernism boils down to, at least in political philosophy, is a belief that "meta-narratives" are not possible because our language is incapable of conveying the same objective meaning to all who hear the meta-narrative. Postmodernist theory was developed to extract an understanding of the subjective filters unwittingly applied by speakers to their speech. Ultimately, this is the exercise in optimism, not pessimism, because Postmodernists would not have bothered to try to understand if they believed objective understanding to be impossible.
For me, Postmodernism ultimately is a misguided and failed attempt to apply Eastern Philosophy to Western Philosophy, an effort first undertaken by Heidegger. Eastern Philosophy and Western Philosophy are entirely incompatible in that the former posits that reality is dynamic unknowable (in a conscious manner) while the latter asserts that the Truth is static and ascertainable. There is no way to harmonize Dynamic Truth and Static Truth, and Postmodernism as a "discipline" proves that. Ultimately, Postmodernism failed to coalesce as a cohesive philosophy because its members did not understand this major disconnect in thinking, which allowed the enemies of Postmodernism to define Postmodernism in Western terms when the Postmodernists themselves could not. In sum, anybody asserting an alternative to "Conventional Wisdom" was branded a Postmodernist, even if the alternative itself was a "meta-narrative" and, therefore, anything but Postmodernist.
Enter Neoliberalism. I have discussed the "Double Truth" (or Double Lie) of Neoliberal doctrine. Neoliberals are, ultimately, Modern Realists, and they are masters at co-opting the political theory of others to advance their agenda. For example, Neoliberal guru Murray Rothbard openly advocated using Leninist tactics to drive the Neoliberal agenda. As the current establishment is Neoliberal, they have discovered ways to apply Postmodern analytics to protect the establishment rather than attack it. Postmodern tactics in the hands of the State amounts to agnotology, i.e., the deliberate creation of ignorance in the populace. This is really nothing new, as "Postmodernism" was well known in ancient Greece, when folks like Plato and Aristotle were the Frank Lutzes of their time.
The key to understanding the difference between a Postmodernist, a modernist and a Neoliberal bullshitter is that a Postmodernist rejects any "meta-narrative" while seeking to understand the social power-driven basis of current meta-narratives, the Modernist offers his own alternative "meta-narrative," and the Neoliberal bullshitter shrugs his shoulders and insists that we can't know anything until everybody agrees (while studiously disagreeing, even when his position is untenable). If you apply this understanding, you will quickly find that a great many people accused of being Postmodernists are actually true blue Modernists while Neoliberals are just opportunists who manufacture dissent and consent at will, as befits their Modern Realist roots.