Dr. Lyle Rossiter, a board-certified clinical psychologist, wrote a book in which he diagnosed the ideology of the left as a tangible mental illness. Perhaps though, liberalism is not so much a novel mental disorder, but a more cleverly disguised form of illness already widely studied since the late ‘60s – narcissistic personality disorder (NPD).
The Mayo Clinic defines NPD as “a mental disorder in which people have an inflated sense of their own importance and a deep need for admiration.” This seems in tune with the fact that liberals believe their policies and platforms fall in the majority -- which they do not.