I was watching this Chris Hedges interview from 2013, when it occurred to me that he was describing Donald Trump.
Is Trump mentally ill? Probably, but that isn't the important point.
The key take-away is that Trump is a product of a sick society, and that society is populated entirely by the wealthy elite. So just replacing Trump with a less boorish member of the same society, such as Pence or Clinton, would still likely leave us with a mentally ill leader.

For years the right-wing, and especially the wealthy elite, have been telling us that the poor are poor because the are lazy, because they are immoral, because they've gotten what they deserve.
Meanwhile the wealthy are living in luxury because they worked harder, because they didn't give into sin, because they are better.

The reality is exactly the opposite.

sociopath:A person with antisocial personality disorder. Probably the most widely recognized personality disorder. A sociopath is often well liked because of their charm and high charisma, but they do not usually care about other people. They think mainly of themselves and often blame others for the things that they do. They have a complete disregard for rules and lie constantly. They seldom feel guilt or learn from punishments.

  It may sound like a bold statement to say that most wealthy people are sociopaths, but in fact there is plenty of scientific evidence behind it.
   A recent NY Times article summed up a study as Rich people just care less. The report was bolstered by a 2008 report from University of Amsterdam and the University of California, Berkeley.

 A prerequisite to empathy is simply paying attention to the person in pain...The more powerful were less compassionate toward the hardships described by the less powerful.

This conclusion is far from unusual. Consider this list:

On 29 July 2010, Britain's Economist headlined "Wealth, Poverty and Compassion: The Rich Are Different from You and Me; They Are More Selfish,"

On 13 December 2010, Rich O'Hanlon of goodmenproject.com bannered "Study of the Day: Rich People Feel Less Empathy,"

On 26 January 2012, the Proceedings of the National Academy of Sciences, PNAS published "Higher social class predicts increased unethical behavior,"

On 27 May 2013, the Journal of Personality and Social Psychology published "Social Class Rank, Essentialism, and Punitive Judgment."

A 2009 survey of 316 CEO's was compared to their company's performance.

 In other words, warm, flexible, team-oriented and empathetic people are less likely to thrive as C.E.O.’s.

 And finally there is this article from 2011.

  In multiple trials that involved both questionnaires and physical-response tests, the researchers found that young adults whose upbringing involved some degree of financial struggle were quicker and more likely to register signs of empathy than young adults who came from affluent backgrounds.

 Interestingly, the article refers back to a 2005 study that casts a great deal of light on why people who lack empathy seem to rise to the top of our capitalist system.

 if a stock trader suffers from some kind of emotional impairment -- that is, brain damage that prevents them from fully experiencing their own emotions -- it may allow them to make more profit on the market, since they can make decisions based more firmly in rationalism.

In fact the average stockbroker is more competitive than a diagnosed psychopath.

More recent studies continue to show the same things.
The wealthy simply don't see you.

Like other studies before it, the researchers came to the stark conclusion that those better off financially unconsciously paid very little attention or downright ignored passersby on the street.

If a rich person did see you, they are often physically unable to care.

In something of a dark irony, the respondents of higher socioeconomic status rated themselves as more empathic — a “better-than-average effect” that Varnum followed up on in a separate study — when in reality the opposite was true. The results “show that people who are higher in socioeconomic status have diminished neural responses to others’ pain,” the authors write. “These findings suggest that empathy, at least some early component of it, is reduced among those who are higher in status.” And unlike self-reports, brain imaging sidesteps “social desirability bias,” where people want to give replies that make them look good or more empathic. “If you’re looking at pictures of people in pain or not in pain, it’s pretty unlikely that you know how to enhance those brain responses,” Varnum tells Science of Us. Moreover, in a 2016 study, Varnum and colleagues found evidence suggesting that people from lower social classes have a more sensitive mirror neuron system — which is thought to simulate the things you see others experience — when watching a video of hand movements. “Our cognitive systems, the degree to which they’re attuned to other people in the environment, is affected by our own social class,” he says.

  There is a clear pattern showing in these scientific studies, and it is the opposite of the right-wing meme. To get to the top you need to be ruthless. Empathy, kindness and a firm set of morals to guide your behavior are traits of the lower classes, not the ruling class.

   The super wealthy are less empathetic and more likely to cheat than those in the working class.

  The growing income inequality means the wealthy rarely rub shoulders with the working poor, and its getting more rare.
   Because they rarely meet regular people it is easy for them to stereotype the poor.

  If you think that's simply some statement by a class war loser, think again. It's what the wealthy elite believeas well.

 In a survey of 500 senior executives in the United States and the UK, 26 percent of respondents said they had observed or had firsthand knowledge of wrongdoing in the workplace, while 24 percent said they believed financial services professionals may need to engage in unethical or illegal conduct to be successful.

 If anything, those numbers are low.

  If you think that is shocking, consider this: that at least one major bank is rumored to have actively sought out sociopaths.

A senior UK investment banker and I [were] discussing the most successful banking types we know and what makes them tick. I argue that they often conform to the characteristics displayed by social psychopaths. To my surprise, my friend agrees.
   He then makes an astonishing confession: “At one major investment bank for which I worked, we used psychometric testing to recruit social psychopaths because their characteristics exactly suited them to senior corporate finance roles.”

 So given that information, consider what it means in Washington, where half of the politicians are successful millionaires.

This sociopathy can be seen in today's politics.

 The insistence by some House Republicans in Congress on cutting financing for food stamps and impeding the implementation of Obamacare, which would allow patients, including those with pre-existing health conditions, to obtain and pay for insurance coverage, may stem in part from the empathy gap.

  It's hard to believe that the politician you supported could have fooled you. That there must have been a reason why he appears to betray his supporters.
   But in fact, the average politician has many of the personality traits seen in the violent criminal underground.