General Discussion

I don't think he even knows how to be honest. He lives in a make-believe reality. He makes up whatever he wants to be reality. He was raised to be that way from birth, and he's not capable of being honest. He is becoming increasingly unable to distinguish between what he's made up and what's actually real.

Now, if this was a magical thing and I could force him to answer one question honestly, that question would be "have you ever molested Ivanka" because that answer (which is most likely yes) would be something his followers couldn't defend.