I don't think "Postmodern Fundamentalist" is an oxymoron at all. Fundamentalists often view everything outside their faith with the same analytical suspicion that academic postmodernists have for classical literature or history. "Atheists believe in evolution because they want to act like animals" is a crude version, but not entirely unlike postmodernism in viewing a theory as a product of motive rather than something describing "reality".
You'd be surprised how much of what Fundamentalists hate reflects their own process of digesting and mapping the world. "Ivory tower academics" are accused of being insular and not connected to real experience. I would say that describes fundamentalists perfectly. "Liberals apply moral relativism to everything" seems to describe people who believe it was OK for Moses to slaughter the Midianites, including women and children, because "God told him to". Most "liberals" hold a more consistent ethic of human rights.
Not that fundamentalists are alone in projecting their own faults onto others. We all do it, and that's why it's so hard to objectively describe society.