Editor's Note: This article is one of 50 in a series about Trump's first two years as president.

There is one presidential duty that each incumbent must eventually bear, but whose timing no one can foresee. Sooner or later in each presidency, something sudden and terrible will occur—an attack, a natural calamity, something as inevitable as a mass shooting or as unusual as a space-program disaster.

In response to these sorrows and emergencies, previous presidents have understood a specific, very important part of their job. At least for a moment, they must shift from head of government to head of state—leader of us all—and reflect the shared sentiments of supporters and critics alike.

In this role (and using examples from only the past few decades), a president can express a broad sense of national grief—as, for instance, Barack Obama did after the 2015 Mother Emanuel gun massacre in South Carolina, in which a 21-year-old white supremacist murdered nine black parishioners at worship. In this role a president can express a sense of national resolve, as Ronald Reagan did after the on-live-TV explosion of the space shuttle Challenger in 1986. Or as Bill Clinton did after an antigovernment terrorist killed 168 people by bombing a federal office building in Oklahoma City in 1995. And in this role a president can reassert enduring national principles, as George W. Bush did in the best speech of his presidency, an address to a joint meeting of Congress nine days after the 9/11 attacks in 2001.

These are the roles all past presidents have assumed and the responsibilities they have borne, as leaders of us, the whole American public. Donald Trump has not risen to this opportunity nor accepted this burden, even once, because he has proved himself incapable of thinking or acting beyond the interests of me.

His callous, tweeted response to the deaths of nearly 50 people in the gun massacre at an Orlando nightclub when he was still campaigning for president—which began, “Appreciate the congrats for being right on radical Islamic terrorism”—prefigured the way he would respond to tragedies when he took office. After thousands of people died in the aftermath of Hurricane Maria in Puerto Rico, Trump awarded his administration, via tweet, “A Pluses for our recent hurricane work” and blamed “a totally incompetent Mayor of San Juan” for anything that had gone wrong. About Hurricane Harvey, in Houston, he seemed mainly to notice its “biggest ever!” size. After the deadliest gun massacre in American history, when one murderer in a hotel tower killed some 59 people and wounded hundreds in Las Vegas, Trump breezily said, “Look, we have a tragedy. [But] what happened is, in many ways, a miracle. The police department, they’ve done such an incredible job.”

The list of instances when Trump said the wrong thing could go on. The more important point is that he’s never said the right thing. Conceivably, weather might have kept him from paying his respects at the World War I battlefield in France last month. Nothing but narcissism kept him from driving the few miles from the White House to the Tomb of the Unknown Soldier, in Arlington, for the presidential duty of laying a wreath on Veterans Day. Any normal president would have recognized the responsibility to show up that comes with his uniquely privileged and powerful job. Trump manifestly did not.

Trump appears to have no moral, emotional, or intellectual ambit that extends more broadly than his own person, or some of his business interests, or perhaps some of his children. It’s not really fair to criticize him for something he cannot do. It would be like criticizing a person born without a larynx for not joining in song. This is how he is made, and how he is limited.

But this particular silence is deafening.

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