Michael D'Antonio is the 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) Despite claiming to be above politics, Donald Trump wants so much to be re-elected that he formed a 2020 campaign committee weeks after moving into the White House. With the power of the incumbency and a head start on his opponents, the President has everything going for him -- except his own big mouth.

In the annals of American politics, no president has done so much to undermine himself as Trump. Anyone else who gained office with an almost 3 million popular vote deficit would have worked hard to lead in a dignified and unifying way.

Trump, however, has insisted on remaining himself.

For more than two centuries, presidents have, with a few exceptions, stood as stable, mature leaders who could even serve as role models for children. Trump has frequently acted as a child, impulsively blurting out claims and condemnations that call into question his fitness to serve. It is these statements that imperil both his presidency and his hopes for re-election.

The most recent examples of Trump's self-destructive speeches have involved his willful distortion of the London mayor's response to recent terror attacks. Over the weekend, and again on Monday, Trump attacked Sadiq Khan for telling Londoners they shouldn't be alarmed by stepped-up police activities in their city.

Only someone determined to cynically exploit the situation would make such a claim and mince the mayor's words. Only a president lacking in presidential fiber would do it twice

Trump's attacks on Khan seem so unnecessary as to be incomprehensible, but they are not as self-destructive as some of the President's other outbursts. For months, the President has sought to ban travelers from six Muslim-majority countries and been rebuffed by federal judges who see this action as a form of religious discrimination. One of the sticking points cited by the courts has been his repeated references to the policy as a "ban" on Muslims. Trump has continued to speak of a "ban," even though the label could hurt his legal case.

More egregious were Trump's attempts to influence FBI Director James Comey, who was investigating his election campaign's possible ties to Russia. Trump took the risky step of firing Comey, and then told Russian officials in the Oval Office that he considered the director to be "crazy" and a " nut job ."

Not surprisingly, Comey is now willing to testify to a Senate committee about a controversy that raises the specter of a President seeking to obstruct justice, which many consider an impeachable offense. (His party's control of Congress makes impeachment unlikely, but two House Republicans have already uttered the "I" word .)

If impeachment comes, it will likely arise out of something the President said or did because he simply couldn't restrain himself. Falling short of such a constitutional catastrophe, the President could risk becoming a one-termer and squander the opportunity he has to enact his agenda.

Despite the chaos, Trump does have a program of sorts. It has included the Muslim ban, the repeal and replace of Obamacare, tax cuts, building a wall on the border with Mexico and infrastructure projects. Remarkably, none of these ideas has been pursued in the orderly way one would expect of a president, and it's not apparent that they will come to pass.

Instead, the White House and the world have been distracted by tweets and scandals of the President's making. His specious claim that he was wiretapped by President Obama and his public embrace of various strongmen, from Turkey's Recep Tayyip Erdogan to the Philippines' Rodrigo Duterte, have all been self-inflicted wounds.

Yet as Trump hurts himself and exasperates his supporters, nothing seems to change his behavior.

As a political matter, Trump's loose talk seems to defy understanding. However, it is consistent with his personality. For as long as he has lived, Trump has struggled to control his mouth. In his business life, this trait made it hard for him to work well with others and thus deprived him of the chance to be far more successful than he was. More specifically, Trump's inability to restrain himself made him difficult to work with, especially outside his core real estate business, and cost him

In his political life, it serves to isolate him from GOP allies as well as foes. House Republicans Justin Amash and Carlos Cubero have both spoken out against him because of his loose talk. And British Prime Minister Theresa May defended the London mayor on Monday, noting that "Sadiq Khan is doing a good job. It's wrong to say anything else."

The President's big talk, in part a consequence of his ego, is also a matter of aggression. Although his extreme words cause real distress, the President seems willing to inflict pain on others in the service of his own impulses. His behavior, which can be frightening, suggests that Trump is driven by the desire to dominate others and to display this dominance in the most flamboyant way possible. Think of the pro wrestler who pins his opponent and then stands with his arms raised and one foot on the other guy's chest. He just has to rub it in.

Follow CNN Opinion Join us on Twitter and Facebook

The need to humiliate others leads Trump to insist that they accept his version of reality, in defiance of what they may see with their own eyes and understand with their own minds. Lawyers and advisers may insist he avoid the risk of talking too much, but this would deprive him of this kind of dominance.

Trump wouldn't be Trump if he heeded their advice. Never a thoughtful or reflective person, he's willing to sacrifice policies and priorities in order to assert power in a particular moment. Given the choice between being president and being Trump, he will always choose the latter, even if it proves to be his undoing.