The most astute analysis of the fate of facts under Trump(ism) is offered by Masha Gessen. Simply put, his blatant lies and “alternative facts” are assertions of power over truth itself. This fits neatly into the broader GOP strategy of casting doubt on validity claims by associating them with the interests and motives of political enemies.
But it’s important not to mistake this state of affairs with genuine skepticism concerning truth claims. For one thing, to claim the power to determine what counts as true presupposes the value of truth claims—otherwise, “alternative facts” would have no value. For another, the utility of facts is bifurcated: undermining facts as unfinished, contested, motivated, etc. is a political strategy devised to mobilize against the enemy; behind the scenes, everyone agrees on lots of facts, from how to serve corporate interests to how best to troll the enemy. Conflating truth and lie thus turns out to be a form of fundamentalism about truth (which, incidentally, helps explain the willingness of religious conservatives to support Trump).
A universe constructed around “alternative facts” is one in which the “right” facts—the ones produced through shared hermeneutic protocols and speech acts—are given decisive power. This is why Propaganda Barbie must lie so transparently: the breathtaking obviousness of her dissembling attests to a faith in the magical sovereignty of language, its power to alter reality directly. An ordinary lie misrepresents, leaving the truth intact; this is why exposing a lie means discovering the truth. Trumpism, like shamanism, equates power with the capacity to speak new, convenient truth into being.