• Latinos
• Asians
• Muslims
• Blacks
• The Disabled
• Women
• Prisoners-of-War

These insults delight his white, under-educated followers. But they have alienated millions of other Americans who might have voted for him.

Here’s Machiavelli’s advice on issuing threats and insults:

• “I hold it to be a proof of great prudence for men to abstain from threats and insulting words towards any one.
• “For neither the one nor the other in any way diminishes the strength of the enemy—but the one makes him more cautious, and the other increases his hatred of you, and makes him more persevering in his efforts to injure you.”

For those who expected Trump to shed his propensity for constantly picking fights once he became President, Machiavelli warned:

• “…If it happens that time and circumstances are favorable to one who acts with caution and prudence he will be successful. But if time and circumstances change he will be ruined, because he does not change the mode of his procedure.
• “No man can be found so prudent as to be able to adopt himself to this, either because he cannot deviate from that to which his nature disposes him, or else because, having always prospered by walking in one path, he cannot persuade himself that it is well to leave it…
• “For if one could change one’s nature with time and circumstances, fortune would never change.”

Then there is Trump’s approach to consulting advisers:

Asked on MSNBC’s “Morning Joe” who he consults about foreign policy, Trump replied; “I’m speaking with myself, number one, because I have a very good brain and I’ve said a lot of things.”

Donald Trump

Machiavelli advised:

• “A prudent prince must [choose] for his counsel wise men, and [give] them alone full liberty to speak the truth to him, but only of those things that he asks and of nothing else.
• “But he must be a great asker about everything and hear their opinions, and afterwards deliberate by himself in his own way, and in these counsels…comport himself so that every one may see that the more freely he speaks, the more he will be acceptable.”

On selecting good advisers, Machiavelli taught:

• “The first impression that one gets of a ruler and his brains is from seeing the men that he has about him. 
• “When they are competent and loyal one can always consider him wise, as he has been able to recognize their ability and keep them faithful. 
• “But when they are the reverse, one can always form an unfavorable opinion of him, because the first mistake that he makes is in making this choice.” 

Among the advisers Trump relied on in his 2016 Presidential campaign: 

• Founder of Latinos for Trump Marco Gutierrez told MSNBC’s Joy Reid: “My culture is a very dominant culture. And it’s imposing, and it’s causing problems. If you don’t do something about it, you’re gonna have taco trucks every corner.” 
• At a Tea Party for Trump rally at a Harley-Davidson dealership in Festus, Missouri, former Missouri Republican Party director Ed Martin reassured the crowd that they weren’t racist for hating Mexicans.

From the outset of his Presidential campaign, Trump polled extremely poorly among Hispanic voters. Comments like these didn’t increase his popularity.

• Wayne Root, opening speaker and master of ceremonies at many Trump campaign events, told Virginia radio host Rob Schilling: People on public assistance and women getting birth control through Obamacare should not be allowed to vote.

Comments like this were a big turn-off among the 70% of women who had an unfavorable opinion of him—and anyone who receives Medicaid, Medicare or Social Security.

• Trump’s spokeswoman, Katrina Pierson, claimed that Barack Obama and Hillary Clinton were responsible for the death of Captain Humayun Khan—who was killed by a truck-bomb in Iraq in 2004.  

Obama became President in 2009—almost five years after Khan’s death. And Clinton became Secretary of State the same year.  

When your spokeswoman becomes a nationwide laughingstock, your own credibility goes down the toilet as well.

Finally, Machiavelli offered a warning that especially applies to Trump: Unwise princes cannot be wisely advised.

• “It is an infallible rule that a prince who is not wise himself cannot be well advised, unless by chance he leaves himself entirely in the hands of one man who rules him in everything, and happens to be a very prudent man. In this case, he may doubtless be well governed, but it would not last long, for the governor would in a short time deprive him of the state.”

All of which would lead Niccolo Machiavelli to warn, if he could witness American politics today: “This bodes ill for your Republic.”