Sam Harris absolutely nails Donald Trump here, and articulates why his non-stop lies are so corrosive.
It is about the most withering critique I've heard of Trump's incessant bragging and bullshitting and is worth watching in full. Key quote:
Honestly, thus far, that [the casualty of truth] is the most harmful aspect of his presidency. Just the complete ruination of any standard of honesty in political discourse and it's astonishing to me. I have not yet accepted that this is even possible, much less actual. I don't think I'm alone, but I'm continually having the bewildering experience that I just cannot believe that this person is president.
It is all focused on this particular aspect of his presidency, where he lies more than any person has ever lied in human history and not only does he get away with it, his supporters seem to delight in his running roughshod over any expectation that a public figure would be honest. It's not a bug, it's a feature for them and that's really disturbing. He has enough people that support him for whom the lying is not actually a problem, it's a technique. It's a kind of naked declaration of power, where he doesn't have to observe your expectations about what is logical or coherent or responsive to facts. He can just say what he wants, because it's the impression he wants to leave with you. He wants a certain language in the air and he just puts it there.
But all lying is just destructive of the social fabric, even so called white lies undermine trust, they undermine relationships, they destroy reputations — that is in a context where people care about the truth. But what's amazing now, we seem to be in some kind of freefall with respect to this and so many people do not care if you are caught lying. And Donald Trump seems to have rewritten the rules.