Consider all the leftist liberals you know and know of. Can't that be said about them all? To live in a land of fantasy, avoiding unpleasant facts and denying those you bump into, would indicate mental and emotional instability by its very nature.
Tammy Bruce describes the liberal mindset so beautifully in her book The Death of Right and Wrong.
She calls them malignant narcissists who are trying to work out their problems through societal experimentation.