Matt Yglesias explains the problem Trump seems to be making for himself with this issue of phoning the families of U.S. servicemen killed in the line of duty. Seems to me the problem flows from the disconnect Trump seems to have between What He Says and What He Does. What He Says is what works for him at that very moment, regardless of reality.
You and I, being much better people, would never say "I have proof" of something unless we actually had it because we'd know it would make us look worse to then not be able to deliver it. Trump says he has proof of something because he's trying to nuke whoever he's arguing with and doesn't consider the ramifications of not being able to back that up.
Or let's say we were on the phone to the father of a fallen soldier who was bemoaning his financial situation. We might blurt out a promise to send him $25,000. We might even regret saying it five minutes later. But I think we'd then say, "Well, I said it. I have to do it. Might as well do it now." Trump says it and doesn't link that to the actual issuance of a check. That can come later if it proves to be necessary.
There are some obvious benefits to having your mind work like that. You're on the campaign trail. You want the votes of those who watch Fox News and have become convinced that there's nothing more horrible than Obamacare, what with it providing affordable health insurance to people in need. But you also want the votes of those who think it's a pretty good idea working pretty well…so what do you do? You promise to replace it with something better, something cheaper, something more efficient and wonderful, etc. That plays to both sides. What you don't do is ask yourself, "How the hell am I going to do that?" because in your mind, saying it and doing it are two separate, unrelated things.
I'm beginning to think that's one of the things his supporters like about the guy. It's certainly calming to think that when he says something that threatens to start World War III, that doesn't necessarily mean he's going to start World War III. And once you accept the premise that that's how he rolls, you can tell yourself your guy isn't lying. He's just not allowing his actions to be dictated by what he said he was going to do.