Arizona -- I agree. Everyone seems to agree that Trump is a pathological liar. Another term used to describe that condition is "pseudologia fantastica". It's considered a mental disorder. Here's how the Learning Mind website describes it in the context of personal relationships, but we might extrapolate to Trump's relationship with certain segments of the populace, his cabinet, his aides and advisors, and more importantly, Congress.
1. Pathological liars will tell you about their own good deeds, and many of them are not even real. They will talk about how many friends they have, when, in actuality, anyone who truly knows them, knows they lie.
2. The pathological lie can break the trust between two or more people in a relationship. Once a lie is found out, anger and frustration begin. If trust isn’t instantly broken by this initial deception, it will soon be if lies continue.
3. This liar will lie so much that they will begin to create more and more fantasies as they go. What started as a single lie about a situation will become embellished as time goes on.
4. A relationship built on nothing but lies cannot survive for long unless you want to live a miserable life. It will be like living with a stranger, and you never know what will come out of their mouth next.
5. Sometimes people lie to keep from hurting others, or they lie to make someone feel better, but liars who are pathological will fib about mundane things. This means, you can ask them what they had for lunch and they will even lie about that. It’s almost as if they can lie about the sky being blue.
6. Pseudologia fantastica keeps liars from fessing up to their deceptions. Just like a child, liars of this caliber will never take responsibility for what they say, and that’s because if they do, their lies will be revealed.
7. Pathological lying places the liar firmly in control of just about everything, so this creates an even larger problem. Why? Because if all they do is tell lies, then all you can do is accept that fact.
8. Pseudologia Fantastica is a personality disorder. This means, without extensive help, the pathological liar will probably never change their ways. Most relationships and friendships with these people will feel like a joke. This is a flaw that could have originated from some sort of trauma early in life, or just from the strong desire to be accepted as a child. If a child is neglected, they will do and say whatever they need to get attention. It is possible that this cry for attention grew into a severe imprint that cannot be controlled. This is the sad part.
I think these above traits largely fit Trump. I have called Trump a master con artist but his extraordinary success in this effort may be due to the fact that he creates his own reality based on lies and then believes his own lies. The most compelling liars are those who believe their own lies. That I think may describe Trump, but if not he is then the most accomplished con artist in history.
In the context of trust and relationships, Trump's trust with Democrats and the media have long been broken. One wonders how long his trust will endure with Republicans in Congress and certain personalities with Fox News. That trust will likely be broken at some point and hopefully that will be soon during the impeachment hearings. When that trust is broken, look for Trump to be removed from office quickly.