In this article I consider Donald Trump as an “antisemantic” president, and link antisemanticism to broader forms of populism. There are three phases in the exploration. I begin by drawing on a model from the past, Stuart Hall’s analysis of Margaret Thatcher’s “authoritarian populism.” Key to Hall’s account was the way it viewed political and discursive domains as intrinsically connected, something eminently applicable in the Trumpian moment. Second, I turn to the antisemantic itself, in order to give it definition. In line with its post-Soviet genealogy, it is tempting to think of the antisemantic as Orwellian, but the analogy is faulty. The Orwellian universe depends on the inversion of meanings (“War is Peace”), but the Trumpian universe (Rudy Giuliani’s “Truth isn’t truth”) attacks the foundations of meaning—the meaning of meaning, as it were. Moreover, in the Trumpian age the internet acts as a dark multiplier: overflowing with the semantic, it thins out meaning not only through its distortions but also through its very profusion. The third phase concerns the counterpart to these patterns, that having undermined some of the standard platforms of truth and meaning, the antisemantic also rests on certain symbolic fixities, not least around the question of boundaries, and most specifically the “uber” symbol of the wall. I end with some notes on how to reconstruct a sense of accountability in meaning, and to think of boundaries that are transitive and generative rather than singular and walled.