Narcissistic personality disorder

Although I have a Masters degree in a mental health field, I rarely resort to the use of terms from the DSM here at this blog or anywhere else in my life. However, for the benefit of the Trump supporters who read this blog, I hereby reprint this from the Mayo Clinic blog:

Narcissistic personality disorder is a mental disorder in which people have an inflated sense of their own importance, a deep need for admiration and a lack of empathy for others. But behind this mask of ultraconfidence lies a fragile self-esteem that's vulnerable to the slightest criticism.