Evidence is piling up that Donald Trump does not really want to be president of the United States.

He certainly doesn't look happy in the job. In his previous life, Trump met whomever he wanted to meet and said whatever he wanted to say. But like all presidents, he finds himself ever more isolated, and his displeasure shows on his face. The loneliness of the job — which so many of his predecessors have ruefully reported — is wearing on him.

And it's more than that. Past presidents also tell us that no one can fully appreciate the dimensions of the job in advance. With no previous political experience, Trump's learning curve has been even steeper than usual, and the more he sees of the job, the less he wants to do it. He balks at the briefings, the talking points, the follow-through.

He was drawn to the fame of it, as he once told me aboard his private jet. "It's the ratings ... that gives you power," then-candidate Trump explained. "It's not the polls. It's the ratings." He loves being the most talked-about man on Earth.

But unlike reality TV stars, presidents aren't famous for being famous. They command the world's attention because they are the temporary embodiments of America's strength, aspirations and responsibilities.

It is a paradoxically self-effacing fame. The job demands that hugely competitive, driven, ambitious individuals — for that's what it takes to win the job — inhabit a role that requires them to be something other than nakedly themselves.

As some Trump associates tell it, he never intended to be elected. But having won the part, he doesn't want to play it, a fact irrefutable after Charlottesville. Rather than speak for the nation — the president's job — he spoke for Trump. Rather than apply shared values, he apportioned blame.

The presidency calls for care and cunning. All successful presidents have known when to say less rather than more. George Washington's second inaugural address was 135 words long.

President Abraham Lincoln often disappointed clamoring crowds, telling them that the risk of a wrong word made it too dangerous for him to deliver a speech.

President Ronald Reagan was famous for cupping his ear and shrugging as he pretended not to hear an untimely question.

Did these men ever itch to win an argument, as Trump did in his Tuesday news conference, with such disastrous results? Of course they did. But a president can't indulge such impulses.

Discipline in thought and speech is the machinery by which a president leads a free people. He hasn't the power to purge his enemies or censor the press. His strength rests on his ability to persuade. His power grows through a record of hard-won results. He seeks friends and respect, not enemies and outrage. Between fired aides (strategist Steve K. Bannon got the boot Friday) and fleeing allies, Trump is losing friends faster than a bully at a birthday party.

Reflecting more and reacting less: That's how a president gets through all seven days of a week supposedly focused on infrastructure without having his advisory council on infrastructure implode. With enough of that focus and discipline, a president might eventually foster an infrastructure bill — an actual law with real money behind it, something more than bluster — that creates jobs and feeds progress and raises spirits.

It's hard work. As shareholders in this enterprise, Americans are asking what disciplined, focused labor Trump performed to pass a health-care bill. What hard ground has he plowed, what water has he carried, to grow the seeds of tax reform?

The president's job is to understand that the world has plenty of troubles in store for this nation. His role is not to add to their number. There will be moments when the president must stir us up, so in the meantime, his task is to keep us calm.

If Trump were still in private business, he would have no trouble diagnosing this situation. A serial entrepreneur like Trump learns to recognize when a venture isn't panning out. Over the years, he splashed, then crashed, in businesses as diverse as casinos, an airline and for-profit seminars. His willingness to fish has always been matched by a willingness to cut bait.

Or, as a veteran boss, he might see his predicament as a personnel move that hasn't clicked. Trump has made many, many hires over his career, and some (as recently as Bannon's) don't work out. "Not a good fit," the saying goes.

The presidency is not a good fit for Trump. It's a scripted role; he's an improviser. It's an accountable position; he's a free spirit. Yes, the employment contract normally runs four years. But at his age and station, what's the point of staying in a job he doesn't want?