In the 1979 bestseller, The Culture of Narcissism, Christopher Lasch diagnosed American culture with a pathological Narcissistic Personality Disorder (NPD). Lasch identified symptoms, some of which are listed in this article.

While everyday narcissism is learned behaviour (nurture) and can be corrected, pathological NPD is akin to nature (and can only be monitored and mediated - but not corrected).

Reagan ushered in the age of trickle down economics, but the only thing that trickled down were the morals, values and world views of the American ruling class (the 1%). As Cain points out, the American ruling class marketed its pathological disorder so broadly, people began learning and modeling narcissistic behaviour as toddlers. That is one of the reasons that I've become convinced that our culture's pathological Narcissistic Personality Disorder is rooted in, and hopefully limited to, the 1%.

In regards to Trump, pathological NPD is on the spectrum of psychopaths and sociopaths who are dangerous to themselves (e.g. Trump's lifelong business, marital and social failures) and dangerous to others (Trump's constant mis-steps and overreach while president, followed by his behaviour as ex-president).

I don't think people can change learned behaviour unless, or until, they see a more beneficial behavioral model. To do that, we need a vibrant movement that is successful enough to seriously challenge the existing narcissistic model that is drowning all of us.