Michael D'Antonio is author of the book "Never Enough: Donald Trump and the Pursuit of Success" (St. Martin's Press). The opinions expressed in this commentary are his.

(CNN) It began with the hosts of "Fox & Friends" beaming at him through the camera, like parents besotted with a first child.

Then, obviously triggered by CNN's Town Hall with former FBI Director James Comey -- "I watched leaking, lying Comey last night. ... I hated to do it" -- President Donald Trump launched into a disjointed rant that revealed his mind to be a frightening and chaotic place.

There, he is practically perfect and just about everyone is out to get him.

The hosts' smiles turned to sober looks of concern as a decompensating Trump lurched from one topic to the next. Highlights included:

• That Comey has "been leaking for years. ... He did an illegal act and he said it himself in order to get a special counsel against me. ... He is guilty of crimes."

• His longtime "fixer" Michael Cohen, who was recently raided by the FBI, is invoking his Fifth Amendment right against self-incrimination in connection with an adult film star's lawsuit "because he's got other things, he's got businesses. ... But I'm not involved." Besides, Cohen only did "a tiny, tiny little fraction" of the legal work Trump needed.

• Investigations into Russian meddling in the 2016 election are a "witch hunt" that have placed a "phony cloud" over him.

• He deserves an "A-plus" grade thus far in his presidency.

• "You look at the corruption at the top of the FBI. It's a disgrace."

• Trump's nominee to run the Department of Veterans Affairs withdrew because Sen. Jon Tester, who revealed serious questions about his performance as White House physician, was motivated by politics.

• Trump's Justice Department, which oversees the most important probe, is filled with people "who shouldn't be there," and thus the President is "disappointed" in the department's performance.

• Trump failed to acknowledge his wife's birthday with a present because "I'm very busy to be running out looking for presents, OK?"

In roughly 20 minutes Trump aired his thoughts and feelings at a manic rate that reminded me of the comedian Robin Williams at his peak.

Hillary Clinton, CNN ("fake news") and Kanye West all got their mentions. The difference, of course, is that Williams was a brilliantly funny man. The President wasn't trying to be funny at all. He was instead making a case for himself as a great leader besieged on all sides by terrible enemies.

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Trump's paranoia, a lifelong trait that he has admitted is part of his makeup, was so evident in his monologue that it constitutes a case study in delusion.

At one point he noted, "I'm fighting a battle against a horrible group of deep-seated people." At another he announced, "Look at others CNN, they will have a council of seven people and of the seven people everyone is against me. Where do they even find these people?"

As "Fox & Friends" co-host Brian Kilmeade then offered his own seemingly disconnected observation -- "I'm not your doctor"-- he expressed what many viewers, including me, must have felt: Trump was on the verge of some sort of meltdown. He needed not an interviewer but an intervention.

Indeed, no medical degree is required to recognize that the President had gone off the rails. Jumping from topic to topic, he offered raw emotions, non sequiturs and florid exaggerations. His VA nominee is deserving because he has a fine son at the US Naval Academy. The porn star he is alleged to have had sex with is "crazy Stormy Daniels."

A president's words matter, which is why every president in modern times has taken care to speak in a coherent and measured way so he could be understood. Some, such as George W. Bush, were chided for their occasional struggles with the English language. But their words never indicated they were unreliable or unhinged.

Trump sounded as if he wrote down a bunch of phrases on little scraps of paper, tossed them into a hat and then took them out, one by one, to shout out on live TV.

Trump's performance was a disturbing reflection of both his undisciplined mind, and his unprincipled character.

It was an abuse of his office, and of the American people who deserve much more than the sloppy, emotional, self-indulgent performer who seems to be pretending he's President.

Even the cheery hosts of "Fox & Friends" turned grim-faced as Trump ranted, and it was left to Kilmeade to put a stop to the babbling.

"We could talk all day but looks like you have a million things to do," he said, as if to remind Trump that he is President of the United States. Trump took the hint and ended the performance, leaving the world to tremble at the madness.