"Postmodernism" doesn't actually mean anything except as a vague insult some intellectuals direct at other intellectuals.
Butfascistspatriotic Real Americans[ent]trade[/ent] have decided it's some kind of code word for "them thar smart peepul alla who is evil cause they done said th' Bible is wrong about th' world bein' flat. Yew know what we all thank about them thar intellectuals!!!!!!"
I'll be sure to watch this later to give me good pointers for my satirical posts. No doubt this "smart guy" will have a really specific definition of postmodernism.