Taking him at his word--absurd, of course--that his actions are intended to make America great again--has to show what that must mean for him.  

His triumphs, then: to favor obscene wealth in taxation; to scrap diplomacy and bait Russia; to fund military horrors he vowed to reduce; to vilify and punish Islamic and Latino vulnerables; to spurn the world effort to reverse climate change; to reject the Iran nuclear deal; to threaten North Korea with nukes; and to decapitate regimes in Syria, Venezuela, and fill in the blank.

Each of these bizarre acts had to be based on his conviction of their supreme importance and his expectation of “winning” outcomes.  Each had to be carried out against resistance by misguided “losers” and perverse and deluded enemies.  The fact that his appalled opposition comprised the vast majority of the conscious, sentient human race carried no weight with him.
 

What can be concluded from this?  How to comprehend it?  Athenians had a name for it.  Sophocles and Euripedes examined it in their dramas in detail, viz.:  “Hubris: a personality quality of extreme or foolish pride or dangerous overconfidence, often in combination with arrogance.”  It was hubris that blinded Oedipus, burned Troy, and killed Achilles.
 

What made tragedy poignant for the Greeks was that the protagonist never realized his hubris until the horrors he provoked brought Nemesis, goddess of retribution, down hard to crush him and his world.  If, perhaps, that old inevitability of doom is still operative, it’s inclusiveness must disturb us.
 

Multitudes would rejoice at Trump’s downfall, imprisonment, even death, but the prospect of living in the disaster of his crash prompts only dread.  Suppose his tax lunacy or trade madness triggers the titanic meltdown in our Funhouse Finance Economy that cognoscenti know is in the cards?  Suppose his Middle School Macho provocations of Iran, or Korea, start a complex, irreversible slide to world war as the Serb ultimatum did in 1914? 

The probability of unimaginable disaster due directly to his bedlamite hipshooting is very high in the short run through financial implosion or world war, and higher yet in the long, from likely irreversible global warming. 
 

What, as Lenin asked, is to be done?  The political party responsible for his rise and election urges you passionately, as a decent person, to get thee to a voting booth soonest and vote for them.  Hell, no, not the Republicans!  They feared him like the plague.  Doing all they feebly could to deny and derail him, they opposed him righteously, wimpily, to the very moment when they didn’t.  When he won...  Then they genuflected and kowtowed.
 

No, no, mes amis: the Dems.  It was the Democrats who gave you Trump.  It was decades of their cynical, contemptible sellout of labor and working people, of students, children, the elderly and sick, for big chips from the putrescent Vampire Squids of Wall Street that greased the skids for the odious grotesque who controls of our collective fate.  And now the party that has conned and screwed you, torpedoed its chance to beat Trump and lied about it, that is doing all in its sleazy power to promote annihilating war with Russia, asks you to drop trou, bend over, and hold your nose again? 
 

One school of thought faults the people for having taken the pretty poison of Exceptionalism and the gospel of Imperialist Proxy Murder of the Deep State’s brain-training game.  Another lays all blame on the profound iniquity of the purveyors of that toxic bullshit that has blasted and burnt so much of the world.  It no longer matters.  The deed is done.  The fait is accompli.
 

However you parse it, an infernal terminal box has been built for America from which there is no exit.  It was done with astonishing want of wisdom, a staggering parochial stupidity and solipsistic blindness that, ignoring all options for correcting our fatal vector, proceeded as inexorably as sunset. 
 

The sorry history of our imperial suicide will be the stuff of legend one day if there are still organs of cognition to receive it.  It will rank right up there with the Pelopponesian War, the Anabasis, and Hitler’s attack on the USSR.