For decades, suspicion of pointy-headed elites in the academy has been a staple of conservative rhetoric, and none more so than postmodernist philosophers and literary critics. By conservative lights, inscrutable scribblers, usually French, were undermining American society by putting out incomprehensible treatises arguing there is no such thing as truth, no opinion is any better than any other, and so on. "The end result is that there can be no more truth or goodness and no need or even ability to make tough choices," wrote Allan Bloom in The Closing of the American Mind.
The conservative view was always about three-fourths caricature — while postmodern writers did have valuable insights in many areas, and were not entirely the gleeful anti-moralists conservatives made them out to be, it is fair to say that Derrida, Foucault, Adorno, and so on were more concerned with pointing out ever more elaborate ways that contemporary society is bad than doing anything about it.
But if there is any political faction that behaves like the most hysterically exaggerated caricature of postmodernism, it is the current Republican Party. If you want an example of a political party whose worldview has become almost entirely socially constructed — divorced from any empirical referent whatsoever — and whose political argumentation is a load of cynical gobbledygook, look no further.
The actual contents of postmodern ideas are a matter of dispute, as they must be for any movement whose members spend half their time blasting salvos of $10 words at each other. Nevertheless, there is a reasonably clear through-line: Postmodernism is a movement that undermined traditional notions of Enlightenment rationality, the idea of absolute truth or morality as things that can stand outside of human discourses and history, the metaphysical "I" of Descartes, and so on; arguing instead for a more contingent version of these concepts as inherently produced and shaped by human society.
Now, as Richard Rorty would say, all that does not mean one cannot demonstrate the falsity of empirical claims (his beef was with metaphysics, not science). But some postmodernists were a bit squirrelly about that point, so let's put on our freshman dorm room bong-seminar propeller beanie and run with Bloom's caricature.
One instructive example of conservative postmodernism comes from the political dispute over the budget. A partial government shutdown is looming by the end of the week over President Trump's demand for a $5 billion down payment on a border wall with Mexico.
All experts in border wall technology, and all people even slightly capable of abstract thought plus 5 minutes of Googling, will agree that a border wall is basically pointless for achieving its stated purpose, for two simple reasons. First, the U.S.-Mexico border is 1,945 miles long, and second, walls are easy to get past — either over, under, or through. Ladders can be raised, grappling hooks can be thrown, steel can be cut, concrete can be sledgehammered or blown up, and tunnels can be dug. Trump himself stumbled onto this by accident once during a characteristic ramble about a (hugely exaggerated) 50-foot wall. "There's no way to get down … maybe a rope."
Of course, all the logic and evidence in the world doesn't matter, because The Wall — like the group of bedraggled refugees that Trump and Fox News inflated into a terrifying horde of Mongol raiders before it — is wholly an empty cultural signifier. Whether it is built or not may have some incidental (and possibly deadly) effects, but its purpose is to alternately inflame and soothe the entirely self-contained neuroses of the conservative base. Conversely, there is the phenomenon of "rolling coal," or other similarly loony acts to "own the libs," which would make no sense whatsoever outside of the modern political context.
Or let's consider the recent conservative court ruling repealing ObamaCare. Texas District Court Judge Reed O'Connor recently ruled that entire law — regulations, Medicaid expansion, and exchanges alike — was unconstitutional because Congress reduced the ObamaCare uninsurance tax penalty to $0 as part of the Trump tax cuts last year. The key assertion is that the rest of the law cannot be "severed" from the mandate and so the whole thing must go. The reasoning here — that Congress basically repealed ObamaCare by accident, despite repeatedly trying and failing to explicitly do so just previously — is preposterous legal Calvinball, as even some conservative legal scholars agree. Every precedent agrees that if part of a law is struck down, the rest goes too only if Congress explicitly structured the law like that. Meanwhile, the idea that the 2017 Congress meant to take down the whole law is so ridiculous that the decision barely mentions their discussion and instead spends page after page on the 2010 Congress (whose intentions are irrelevant to the matter at hand).
The decision partakes not only of the post-truth postmodern style, but also of the worst rhetorical tics of the worst postmodern writers — substituting silly, obscurantist dialectics and maddening pretzel logic for honest writing and clear reasoning. (Jacques Marie Émile Lacan, eat your heart out!) It is a cynical, nakedly anti-democratic attempt to achieve by legal decree what the Republican Congress could not achieve through the legislative process.
Now, it would be a mistake to somehow blame continental philosophers for this development. I think it's safe to say Trump is not reading any Jean-François Lyotard. On the contrary, the political and moral rot of the Republican Party is happening according to its own internal dialectic — indeed, I daresay much postmodern writing (taken, as with any inflated windbag philosophy, with a large grain of salt) can be quite useful in understanding how it's happening and how to confront it.
But let us at least be clear that if anyone is introducing moral relativism into American society, and undermining shared understandings of basic facts, it is the Republican Party.