It is inevitable that a president — carrying out impossibly weighty responsibilities, in a very public capacity, while the opposition and press fasten on every peccadillo — is going to feel besieged, misunderstood, or otherwise unfairly treated.

This naturally often leads to private venting, brooding, plotting and perhaps even an overly defensive outburst in public.

The Prussian statesman Otto von Bismarck captured what might have been the experience of more than one president when he reportedly told his personal assistant one morning, “I could not sleep, I hated all night.”

LBJ and Richard Nixon felt grievously ill-used and slighted, and Bill Clinton believed that when he had an affair with an intern, lied about it under oath, and got caught, something terrible had been done to him. There’s been much commentary lately about Clinton’s contrition during the Lewinsky affair, but there were also displays of anger and self-pity.

That said, with the exception of, most notably, Andrew Johnson, who openly raged against his partisan enemies, the presidential mode is to try to keep feelings of persecution under wraps. Not Trump, who unashamedly airs these feelings and uses them as a weapon.

This has been his practice his entire adult life, and it has worked for him. He has lobbied to be considered wealthier by the keepers of lists of wealthy people; scratched and clawed for more media coverage; sought to outlast and wear down anyone in a dispute, unwilling to be — as he sees it — cheated of money, attention, or glory.

As he put it in an interview early in the Republican nominating contest in 2015, “I do whine because I want to win and I’m not happy about not winning and I am a whiner, and I keep whining and whining until I win.”

One of his favorite words is “unfair.”

Part of the strength of Trump’s bond with his base is that his voters feel sneered at and attacked, and so identify with his plaints.

Trump also gains credence for his aggrieved view of the world by the constant overreach of his opponents. Just because someone always thinks he’s being treated unfairly doesn’t mean that he isn’t, indeed, being treated unfairly.

A passage in his letter to Speaker Nancy Pelosi that truly lands is his bitter account of the Russian investigation, during which the FBI abused its powers, the most outlandish speculation was routine fare on cable news, and a special counsel investigation blighted the first couple of years of his administration.

He’s right to point out that impeachment is, essentially, an extension of this episode. It might be the best example since Hillary Clinton’s “deplorables” line of an affront that both Trump and his voters can take personally.

Trump will wave the bloody flag of impeachment until next November as an example of how Democrats tried to get rid of him — and disregard his voters. The timing on the cusp of an election year means impeachment works perfectly for this argument looking at the past and to the future; it (partly) invalidates the 2016 election, while also short-circuiting the 2020 vote.

Still, Donald Trump occupies the most powerful office in the world, bedecked with all the majesty and pomp and circumstance that a republic can muster. The media hangs on his every word and tweet, and his name, long after his buildings are gone, will remain part of American history.

This is not the profile of anyone’s victim, and Trump would do more honor to the office if he brooded more, and vented less.