Outsider:  If an individual makes an untrue factual statement, is provided with the evidence that the statement is untrue and KNOWS it's untrue, he is, in fact, a liar.  We all know (including you) that Mr. Trump is a habitual liar  
"Pathological lying (also called pseudologia fantastica and mythomania) is a behavior of habitual or compulsive lying. [1][2] It was first described in the medical literature in 1891 by Anton Delbrueck.[2] Although it is a controversial topic,[2] pathological lying has been defined as "falsification entirely disproportionate to any discernible end in view, may be extensive and very complicated, and may manifest over a period of years or even a lifetime".[1] Individuals may be aware they are lying, or may believe they are telling the truth.[citation needed] Sometimes however, the individuals may be lying to make their lives seem more exciting, when in reality they believe their lives are unpleasant or boring"  You suggest this fits DJT..you may be right. GC