Psychologists call them defense mechanisms. There are around fifteen or so common defense mechanisms and they range in manifestation from denial to rationalization to reaction formation. In mentally healthy humans they are often positive psychological contrivances utilized to preserve mental and emotional stability.
In mentally unstable humans who sometimes present with exaggerated defense mechanisms, the behavior of such individuals can be consequently problematic. An unstable person in denial can become so deeply entrenched in that defense mechanism as to be incapable of dealing with their difficulties directly, as they refuse to acknowledge (that is, they deny) any problem to begin with.
Donald Trump is a deeply mentally unstable person whose most common defense mechanism presents as projection. “Projection,” according to psychologist Kevin FitzMaurice, “is the attribution to others of your own negative self-concepts. This occurs when you want to avoid facing negative self-concepts about your behaviors or intentions, and you do so by seeing them in other people instead.”
For example, in recent reports about chaos in the White House, Donald Trump pushed back directly when he tweeted on November 15th: “The White House is running very smoothly and the results for our Nation are obviously very good. We are the envy of the world.” Yet, on the same day Trump tweeted, “The inner workings of the Mueller investigation are a total mess … They are screaming and shouting at people, horribly threatening them to come up with the answers they want. They are a disgrace to our Nation …”
Notice Trump’s choice of violent or chaotic words: “total mess,” “screaming and shouting,” “horribly threatening,” “a disgrace.” Trump, through the defense mechanism of denial, is describing his own administration. Trump is witnessing his own frenetic and besieged White House coming apart and trying to project the chaos he sees to where he desperately needs it to be, in the offices of the Mueller investigation. Meanwhile, back in reality, the Mueller investigation is proceeding apace, ticking over like the well-oiled machine that it is, moving forward with the very glacial, competent, relentless iciness that Donald Trump can only dream about for his own chaotic, ruined presidency.