I really think he lives in an egomaniacal narcissistic bubble where his mind just reshapes reality as it sees fit, everything he says must be true, no one knows more than him about any given subject, and he can never, ever be wrong. So yes, I do think he can be delusionally narcissistic enough to believe what he's saying must be true, just because he can never be wrong.
But on top of that, he's also a completely callous sociopath who doesn't care anyway. Other people are either foes for him to play himself off of to establish his (in his mind) superiority and dominance, or just props in The Donald Show, like his adoring fans who only serve to feed his ego.
