It’s hard to know exactly what is going on in that brain, but science lends a clue. Psychologists wonder if narcissists are defined by extremely high self-esteem or by extremely low self-esteem that they are trying to mask. The current consensus seems to be that they are marked by unstable self-esteem. Their self-confidence can be both high and fragile, so they perceive ego threat all around.

Damon Winter/The New York Times        

Trump Is Getting Even Trumpier!

International New York Times | 19 July 2016

David Brooks

Does anybody else have the sense that Donald Trump is slipping off the rails? His speeches have always had a rambling, free association quality, but a couple of the recent ones have, as the Republican political consultant Mike Murphy put it, passed from the category of rant to the category of full on “drunk wedding toast.”

Trump’s verbal style has always been distinct. He doesn’t really speak in sentences or paragraphs. His speeches are punctuated by five- or six-word jabs that are sort of strung together by connections that can only be understood through chaos theory: “They want the wall … I dominated with the evangelicals … I won in a landslide … We can’t be the stupid people anymore.”

Occasionally Trump will attempt a sentence longer than eight words, but no matter what subject he starts the sentence with, by the end he has been pulled over to the subject of himself. Here’s an example from the Mike Pence announcement speech: “So one of the primary reasons I chose Mike was I looked at Indiana, and I won Indiana big.” There’s sort of a gravitational narcissistic pull that takes command whenever he attempts to utter a compound thought.

Trump has also always been a little engine fueled by wounded pride. For example, writing in BuzzFeed, McKay Coppins recalls the fusillade of abuse he received from Trump after writing an unflattering profile (he called Mar-a-Lago a “nice, if slightly dated, hotel”).

Trump was so inflamed he tweeted retaliation at Coppins several times a day and at odd hours, calling him a “dishonest slob” and “true garbage with no credibility.” The attacks went on impressively for over two years, which must rank Coppins in the top 100,000 on the list of people Donald Trump resents.

Over the past few weeks these longstanding Trump patterns have gone into hyperdrive. This is a unique moment in American political history in which the mental stability of one of the major party nominees is the dominating subject of conversation.

Everybody is telling Trump to ratchet it down and be more sober, but at a rally near Cincinnati this month and in his Pence announcement speech on Saturday, Trump launched his verbal rocket ship straight through the stratosphere, and it landed somewhere on the dark side of Planet Debbie.

The Pence announcement was truly the strangest vice-presidential unveiling in recent political history. Ricocheting around the verbal wilds for more than twice as long as the man he was introducing, Trump even refused to remain onstage and gaze on admiringly as Pence flattered him. It was like watching a guy lose interest in a wedding when the bride appears.

The structure of his mental perambulations also seems to have changed. Formerly, as I said, his speeches had a random, free-form quality. But on Saturday his remarks had a distinct through line, anchored by the talking points his campaign had written down on pieces of paper. But Trump could not keep his attention focused on this through line — since the subject was someone else — so every 30 seconds or so he would shoot off on a resentment-filled bragging loop.

If you had to do a rough diagram of the Trump remarks it would be something like this: Pence … I was right about Iraq … Pence … Hillary Clinton is a crooked liar … I was right about “Brexit” … Pence … Hillary Clintons ads are filled with lies … We’re going to bring back the coal industry … Christians love me … Pence … I talk to statisticians … Pence is good looking … My hotel in Washington is really coming along fantastically … Pence.

Donald Trump is in his moment of greatest triumph, but he seems more resentful and embattled than ever. Most political conventions are happy coronations, but this one may come to feel like the Alamo of aggrieved counterattacks.

It’s hard to know exactly what is going on in that brain, but science lends a clue. Psychologists wonder if narcissists are defined by extremely high self-esteem or by extremely low self-esteem that they are trying to mask. The current consensus seems to be that they are marked by unstable self-esteem. Their self-confidence can be both high and fragile, so they perceive ego threat all around.

Maybe as Trump has gotten more successful his estimation of what sort of adoration he deserves has increased while the outside criticism has gotten more pronounced. This combination is bound to leave his ego threat sensors permanently inflamed. So even if Candidate Trump is told to make a normal political point, Inner Boy Trump will hijack the microphone for another bout of resentful boasting.

Suddenly the global climate favors a Trump candidacy. Some forms of disorder — like a financial crisis — send voters for the calm supple thinker. But other forms of disorder — blood in the streets — send them scurrying for the brutal strongman.

If the string of horrific events continues, Trump could win the  presidency. And he could win it even though he has less and less control over himself.