In ancient Greece, the statesman was often contrasted with the tyrant. A statesman ruled for the common good; the tyrant ruled for a private good. The statesman has a valid title to rule; the tyrant lacks such a title or legitimacy. The statesman is a friend to those he governs; the tyrant rules more by coercion than persuasion and is content to view those he dominates as enemies. The statesman seeks justice; the tyrant embodies injustice. The statesman acts moderately as he controls his appetites; the tyrant is marked by extremism with an inability to control his appetites. Beyond these broad themes, there is a specific difference with how these two types of rulers act in a particular situation--who they befriend while in office.
Plato's Gorgias offers an insight into friendship and justice.
In the Gorgias, Plato describes the way rulers seek to avoid injustice by seeking justice whereby the moderate seek to befriend the moderate and avoid the immoderate. Moreover, they seek to encourage the immoderate to be moderate and treat each other, with equality. For democratic politicians, like the president, this is an almost daily task. They meet with their constituents, fellow politicians, or those they want to become their followers. Their constituents are not necessarily their supporters nor are they their opponents. Often, they are people who meet the president on some special occasion or through his official duties. In these small moments, often out of the view of the press but sometimes captured by them, we see how presidents treat those who are not like them. The president often makes friends most easily with those he understands or sees as his equals and treats as his equals. Sometimes, but not always, they may not share his vision, or they simply seek to benefit from him. A president who is comfortable with the public can make friends equally with the powerful as well as the weakest or most vulnerable for he sees no difference between them. For others, though, the strong are to be courted and the weak to be avoided since the former can hurt them and the latter cannot help them. How a president approaches the strong, the weak, and their equals reflects their character and indicates whether they are closer to being statesman or a tyrant.
Plato’s Gorgias tells us more about Trump than we may want to know.
A particular passage in the Gorgias (510c-d) illustrates this point. Plato describes, through an exchange between Socrates and Callicles, how, in contrast to a statesman, the tyrant behaves. In this exchange, we learn some lessons about how Obama ruled and see the potential for how Trump is likely to rule.
Socrates: Then wherever a brutal and uneducated tyrant is the rule, won’t he surely be afraid of anyone in the city who is far better than him, and wont he be quite unable to become a friend to him with all his mind?
Callicles: That’s so.
Socrates: And if someone is far worse than himself, he won’t be a friend either; for the tyrant, will despise him, and never treat him seriously as he would treat a friend.
Callicles: That’s true too.
Socrates: Then the only friend to such a man worth consideration who’s left is whoever has a similar character, blames and praises the same things, and is willing to be ruled by the ruler and to be subject to him. This man will have great power in this city; no one will do injustice against him without being sorry for it. Isn’t it so?
Socrates: then suppose some young man in this city thought “how might I win great power so that no one does injustice to me?” Apparently, this is the road for him; he must accustom himself from you to enjoy and hate the same things as the tyrant, and manage to be as like the tyrant as possible. Is that the way?
If we consider this exchange and compare it with how Obama, Chris Christie, and Trump interacted, we see a lesson in the difference between statesmanship and tyranny. In the differences, we get an insight into their character and how they rule. Moreover, we see a lesson for Trump’s son Barron.
Obama is Trump’s superior.
The first exchange describes Obama and Trump’s meeting after Trump’s victory. In the videos of the meeting, Trump looked ill at ease. As many commentators noted, Trump had a lot to learn about the presidency. Trump recognized that Obama was his superior and Trump didn’t want to be Obama’s friend. Trump’s failure to intimidate him with his Roy Cohn’s methods, showed Obama’s character. Obama showed what Trump lacks--grace under pressure. Moreover, how Obama treated New Jersey governor Chris Christie shows his ability to treat those in need as his equal.
Christie is Trump’s inferior and Trump humiliates him for it.
The second exchange captures how Trump treated Chris Christie. Trump humiliated him on several occasions. Trump did not see him as an equal.  Christie was rival who had lost. Moreover, other Republicans disdained him. As Mike Kelly explained, many Republicans believed that Christie had betrayed his party and his country when he appeared to support Obama. Christie needed Obama’s help after Hurricane Sandy devastated New Jersey. When Obama’s visited, he treated Christie as an equal. He treated him as a friend in need. In response, Christie’s relief was plain to see. The photos appeared to capture an embrace between the men, for which Christie was seen as a traitor. Republican critics argued he should have put party loyalty and loyalty to Mitt Romney before his people or his country.
Birds of a feather flock together especially when they can settle scores.
The third exchange we see the way that Bannon, Kushner, and Flynn have joined with Trump for they see this as a way to gain power. They are men of a similar character who praise what he praises and blame what he blames. Above all, this role, allows them to indulge the most tyrannical desire—to dominate others. They want to have the power to harm their enemies and help their friends. In their respective roles, they can wield great power for they become an extension of the President. They can use, or usurp, the office’s power and prestige, and the ingrained institutional legitimacy, to pursue their feuds, deals, and schemes. Trump learned these lessons from Roy Cohn who taught him how to be an unjust man and do it legally. Trump remains proud of the way that Cohn would brutalize people on his behalf. If we look closely, we can see a similar approach by Trump’s inner circle although they seek less publicity. Take, for example, Jared Kushner and his relationship with Chris Christie. Once we understand the background, we can see that the Christie humiliations come into sharp relief. Chris Christie was a U. S. Attorney who helped to prosecute Charles Kushner, Jared Kushner’s father. Trump will have humiliated Christie to settle the score for Kushner. The same can be seen with Lt. General, Michael Flynn who is the president’s National Security Advisor. He has scores to settle in Washington. To be sure, politics has always been a way to settle scores without recourse to violence. However, what is different here is that it appears an overriding aim of Trump and his inner circle. Their first concern is with revenge and only secondarily, if at all, to understand the common good or to see justice.
Barron has a chance to save his democratic soul.
In the final section, we see the lesson for Barron. For Trump’s other children, the lesson is impractical as they are already initiated into his life. Their characters are already formed. For Eric and Don Jr, they already believe they have great power so they are less worried someone will try to inflict an injustice on them. In New York, they have grown up within their father’s domain so they already know privilege, power, and the ability to hurt their enemies. They are Roy Cohn’s stepsons for they already know how to wield a certain type of power. The lesson here is for Barron for he still has a chance to develop a democratic soul. If he learns the wrong lessons from his time in the White House, he will want to become politically like his father.
For Barron, the challenge will be to separate his father, as father, from his father as a political man. If he can, then he can develop a democratic soul. To do this, though, he needs to see America as a democratic nation. He needs to see that in America equality creates justice. He needs to escape the political ethos where dominance and subservience define justice. Unlike the other children, he can escape Roy Cohn’s influence. As Thucydides wrote over 2600 years ago, the strong rule the weak and only between equals is there justice. In 1776, America was founded on the belief, hope, experiment, that a people govern themselves as equals. America is founded on the hope that a government of the people, by the people, and for the people, would ensure justice. America would be a nation where the strong do not rule the weak for all equal before the law. Barron still has time to learn this lesson.
 For a good discussion of the idea of statesmanship see Wendell John Coats, Statesmanship: Six Modern Illustrations of a Modified Ancient Ideal Susquehanna University Press,1995.
See also Plato Statesman translated by C. J. Rowe in Plato: Complete works edited by John M. Cooper p.294
“The ‘statesman’—in Greek the politikos, whence the Latinized title Politicus by which the dialogue is alternatively known—is understood from the outset as the possessor of the specialist, expert knowledge of how to rule justly and well—to the citizens’ best interests—in a ‘city’ or polis, directing all its public institutions and affairs.”
 See for example, Leo Strauss On Tyranny: Corrected and Expanded Edition, Including the Strauss-Kojève edited by Victor Gourevitch and Michael S. Roth, p.75 fn51.
 See Robert W. Hall Plato Vol IX Political Thinkers edited by Geraint Perry p. 81 https://books.google.co.uk/books?id=gEEio0_s2V0C&pg=PA81&lpg=PA81&dq=statesman+persuades+tyrants+coerce&source=bl&ots=ORbZehzSvP&sig=pCaogPnIqwtiDFO4qGpWnbC0IX8&hl=en&sa=X&ved=0ahUKEwj35dK42NTRAhXHvBoKHWCsCygQ6AEIHzAB#v=onepage&q=statesman%20persuades%20tyrants%20coerce&f=false
 Plato, Gorgias, Translated with Notes by Terence Irwin, Clarendon Press, Oxford 1979.
 Trump’s insistence, despite all verifiable evidence to the contrary, that Obama lacked a valid US birth certificate is but one of the milder techniques that Roy Cohn taught Trump.
 In an interesting parallel, Lyndon Johnson who became president after John F Kennedy was assassinated, was often criticized for the same reasons. Johnson was criticized and felt slighted about his standing as president until he won a clear mandate at the next election.
Here Christie explains that he was doing his job to help his constituents. http://www.nj.com/politics/index.ssf/2015/04/christie_on_embracing_obama_after_hurricane_sandy_i_was_doing_my_job.html
 “If you need someone to get vicious toward an opponent, you get Roy,” he told Newsweek in 1979.
A year later, pressed by a reporter from New York magazine to justify his association with Cohn, he was characteristically blunt: “All I can tell you is he’s been vicious to others in his protection of me.”
He elaborated in an interview in 2005. “Roy was brutal, but he was a very loyal guy,” Trump told author Tim O’Brien. “He brutalized for you.”
 “The motive: Christie as U.S. attorney was involved in the prosecution of Charles Kushner, who was sentenced to prison in 2005 on 18 counts of tax evasion, witness tampering and making illegal campaign donations.” http://www.usatoday.com/story/news/politics/2016/11/16/trump-kushner-christie-transition/93992468/
 See Republic 572c-573c
 On the issue of dominance and submission see https://talkingpointsmemo.com/edblog/dominance-and-humiliation-no-middle-ground This approach also fits the view presented by Callicles throughout Gorgias as well as Alcibiades in the Republic.
 See Thucydides The History of the Peloponnesian War 5.89.1.
 1 Corinthians 15:33