It wouldn’t be surprising to learn that Donald Trump despises the Washington Post—but who knew that he’s a fan of Emily Post?

Early Monday morning, the president of the United States seemed to be channeling the legendary American etiquette doyenne when he tweeted: “It is amazing how rude much of the media is to my very hard working representatives. Be nice, you will do much better!”

This is not the first time that President Manners has schooled members of the news media in appropriate decorum.

“Don’t be rude!” Trump commanded CNN White House correspondent Jim Acosta during a pre-inaugural Jan. 11 press conference, refusing to take Acosta’s question after the latter objected to Trump’s trash-talking of his network.

Sam Donaldson, ABC’s legendary White House correspondent who was occasionally called “rude” for his loud and persistent grilling of presidents, said about Trump’s tweeted admonition: “Remember what [Jimmy Carter’s press secretary] Jody Powell used to say? That’s like being called ugly by a frog.”

Donaldson told The Daily Beast that nearly three decades ago, when he and Diane Sawyer co-anchored an ABC program called Primetime Live, he, too, was the object of Trump’s etiquette education.

“In 1990 I interviewed this guy about his business,” Donaldson recalled. “And in the course of the interview, about 13 minutes long, he accused me of being rude to him, he accused me of being ignorant, and he accused me of being out to get him. And I wasn’t out to get him, but yes, I was ignorant about his business, although I knew better than to think that he could service the debt for the airline, for the Plaza Hotel, and for the Taj Mahal, because he didn’t have enough money! And so he lost them all to the banks, right?”

Donaldson continued: “I interviewed that guy. And it passed from The Donald’s lips that I am rude, ignorant and out to get him. Hello. I know the boy. You know the boy. Everybody really knows the boy. It was a lot of fun, all of this. But unfortunately, it’s now very serious.”

Indeed, during the 2016 campaign the president tagged his political opponents with boorish nicknames, called Mexicans “rapists,” mocked Megyn Kelly’s menstrual cycle, mimicked the physical disability of New York Times reporter Serge Kovaleski, encouraged his supporters to beat up protesters at rallies, threatened to “bomb the shit” out of ISIS, and advised American businesses that move overseas “to go fuck themselves.”

And let’s not consign to collective amnesia that hardly-ever-mentioned-these-days Access Hollywood video.

“Who hasn’t he insulted, at least during the campaign, and even while he’s been president?” Donaldson demanded. “If there’s a group of three people he hasn’t found to insult, I don’t know who they might be.”

Donaldson, never one for verbal restraint, likes to refer to the 45th president as “the ‘EVI’—the egomaniacal vulgarian ignoramus.”

But apparently, at least for now, the press corps is dealing with President Polite.

“That’s really rich, isn’t it, and more than a little bit obnoxious,” Lucy Dalglish, dean of the University of Maryland’s Philip Merrill College of Journalism, said about Trump’s complaint. “And who set the tone for that? Just think of all the things he’s said and done to and about people. Is he surprised? It goes both ways.”

Dalglish, a former journalist and longtime First Amendment lawyer, added: “I can’t think of anybody in the media who has actually been rude. And ‘be nice’? What does that mean? ‘Don’t challenge me’? ‘Don’t ask questions’? “Don’t expect us to dig for data’? I’m just kind of bewildered.”

It’s difficult to know what exactly provoked this morning’s censorious tweet, much as it remains a mystery what might have prompted the president’s accusation nine days ago that his “bad (or sick)” predecessor wire-tapped Trump Tower.

Perhaps Trump was simply doing a bit of mischief, trolling the press for his own amusement.In a compelling New Yorker magazine report on how the Trump White House is working to delegitimize the mainstream by legitimizing rightwing crackpots in the briefing room, author Andrew Marantz calls the president “the world’s most gifted media troll.”

Or maybe Trump’s tweet was inspired by the merciless drubbing administered to presidential counselor Kellyanne Conway Monday during a series of morning show appearances in which she tried to defend her unsupported claim—to the Bergen (N.J.) Record—that Barack Obama could have spied on Trump using “microwaves that turn into cameras.” (The president, who apparently has a protective streak, frequently defends his former campaign manager.)

Or maybe it was White House Press Secretary Sean Spicer’s unpleasant Saturday encounter at a Washington, D.C., Apple store with a fellow customer, a non-journalist who kept her cell phone recording as she berated him repeatedly for “work[ing] for a fascist” and “lying to the American people.” (In fairness, the president is far less protective of Spicer, and has even publicly nitpicked his performance.)

During Spicer’s Monday briefing for the White House press corps—which turned fractious when reporters for NBC News, Peter Alexander and Hallie Jackson, stubbornly demanded to know which of the president’s various claims should or should not be taken literally—the press secretary was asked what he thought about the boss’s tweet.

“I think I’ve been asked for my personal opinion several times; that’s not my job,” he dodged. “I don’t get up here to speak for myself. I speak for the president. I think he has been very clear he doesn’t believe some of the behavior and the reporting has been appropriate…I will let the tweet speak for itself.”Others, however, were happy to offer some textual analysis.

“Our job isn't to be nice or not nice. It’s to cover the news,” said Kyle Pope, editor and publisher of the Columbia Journalism Review. “And that is the fundamental point that the president doesn't understand: critical stories or reporting don't amount to some kind of personal attack or a ‘meanness’ on the part of the reporters. We live in the world of information, and care less about whether it's nice or not nice and more about simply whether it's true.”

Frank Sesno, director of the School of Media and Public Affairs at George Washington University, echoed Pope’s sentiments in a text message: “Journalists are not paid to be 'nice.' They're paid to be reporters—sometimes tough, focused on accuracy in search of truth. Respectful but skeptical.”

Independent journalist Sharyl Attkisson, a former CBS News correspondent, was dismissive about the significance of Trump’s tweet. “It’s funny. Who cares?” she emailed, although she added that niceness has limited application. “As an aside, I am polite to the Trump folks, as I try to be to all, and I haven’t had any luck getting interviews the last 4 months. I was polite to the Obama folks and didn’t have much luck with them, either.”

Nation magazine editor Mark Hertsgaard—whose groundbreaking 1988 book, On Bended Knee, chronicled the Reagan White House’s conquest of a pliable, subservient Washington press corps—said Trump’s complaint is “laughable,” because, among other reasons, “sometimes the watchdogs have to bark pretty loudly so that they can get through to the people in the palace.”

Hertsgaard, who has just edited the special Nation section, “Media in the Trump Era,” said the louder, the better.

“It’s very interesting to watch the Washington press corps begin its rediscovery of its vestigial adversarial responsibilities,” he told The Daily Beast. “The Washington press corps by instinct is not adversarial—they believe themselves to be a part of a governing elite--and it’s interesting to see how with Donald Trump, they’ve been faced with a choice: Either go along and find your adversarial past, or get down on the knee pads again.”