As per White House tradition, a press corps typically tags along with the president, providing coverage of his outings in case some world-altering event occurs around the country's most public figure.

But maybe not, if Donald Trump has anything to do with it.

That's the concern among the "protective pool" of journalists, who were given the slip again this week when Trump dashed out on Tuesday night to dine at Manhattan's 21 Club.

Outrage ensued as journalism advocates argued that wherever the president-elect goes, so goes potential news.

Historic examples may bolster their argument.

The pool comprises roughly a dozen journalists — writers, producers, radio and TV reporters — assigned to cover the president's movements, even when it comes to humdrum outings, such as a family meal near Trump Tower.

The gig could mean following the president to Sarasota, Fla., where he's scheduled to read to a class at Booker Elementary School.

Or following the president to a month-long vacation at the South Carolina estate of a wealthy adviser.

Or riding along in a motorcade for a presidential parade through downtown Dallas.

'We want to be in the motorcade'

"We want to be in the motorcade just in case something happens," says Steven Thomma, a senior White House correspondent with McClatchy. "It's called a protective pool for that reason."

That Florida elementary school? That was where George W. Bush first learned of a second jetliner slamming into the World Trade Center on Sept. 11, 2001. Bush held a briefing on the attacks from Sarasota, in remarks that would eventually lead the nation into a protracted "war on terror."

George W. Bush is informed by his chief of staff, Andrew Card, of the attacks on the World Trade Center during a school reading event in Sarasota, Fla. (Paul J. Richards/AFP/Getty Images)

That South Carolina retreat? It was where Franklin D. Roosevelt began complaining of abdominal pains in April 1944. Reporters travelling with the president began questioning Roosevelt's health. He died a year later.

As for the parade in Dallas? UPI reporter Merriman Smith recalls hearing three "cracks" on Nov. 22, 1963 — gunfire that killed John F. Kennedy. Smith, riding in a pool car in the motorcade, grabbed the mobile radiotelephone and relayed the breaking news to the world via Teletype: "Kennedy seriously wounded ... perhaps seriously, perhaps fatally ... by assassin's bullet."

Trekking solo to D.C.

Since his election win on Nov. 8, Trump has twice bucked the tradition of having an accompanying pool of journalists follow his activities. Last week, he travelled to Washington from New York without the pool.

On Tuesday, around 6:14 p.m., Trump spokeswoman Hope Hicks issued a "lid" on the evening, a term that typically guarantees the president has retired for the day. Instead, Trump's motorcade reportedly departed about an hour later for the 21 Club.

Reporters only learned of the outing by happenstance: a Bloomberg reporter dining at the same restaurant tweeted a photo.

twitter! To avoid any more confusion, reposting from *last* night at the right location 21 Club w/ <a href="https://twitter.com/realDonaldTrump">@realDonaldTrump</a> <a href="https://t.co/ah4pBo9fAX">pic.twitter.com/ah4pBo9fAX</a> —@RiggsReport

"We don't care if he's going to stop and look in the window of Saks and buy a tie," says Thomma, a former president of the White House Correspondents Association. "We do care if he's going to walk out arm-in-arm with the president of France and we find out he's just reached an agreement on a NATO decision."

If it was an honest mistake, as Hicks has claimed, that casts doubt on the Trump transition team's organization.

The White House Correspondents Association issued a statement Wednesday calling Trump's press-dodging behaviour "unacceptable." Earlier this week, after the Washington trip, it warned that such a habit "could leave Americans blind about his whereabouts and well-being in the event of a national crisis."

Security personnel stand at entrance of the 21 Club in New York on Tuesday, where Trump was having dinner with his family. He ventured out after a spokesperson told pool reporters he had retired for the evening. (Carolyn Kaster/Associated Press)

This is not about the Fourth Estate whining about facilitation of the presidential "body watch" to make their jobs simpler. Nor is it about press entitlement, according to the Society of Professional Journalists.

"Without the presence of journalists and news organizations, the public is forced to receive news about this country's leader through one lens — that of the government," said society president Lynn Walsh.

'Two-way relationship'

Pool journalists function as the eyes and ears of the public. Their access to the president, Walsh says, is access for the American people. President-elect Trump will soon need to learn he has shed his privileges as a private citizen.

There are no official rules governing the president's relationship with the press.

Ivanka Trump and her husband, Jared Kushner, leave the 21 Club after dining with the president-elect. (Kathy Willens/Associated Press) But the pool tradition has long existed with the tacit understanding that "each needs the other," says Martha Joynt Kumar, a scholar of the White House and presidential relations with media.

The press expects to know whom the president, as the initiator of policy, is meeting with, she said.

"The president needs the press in order to govern, and for the press, the president is an important source of news," Joynt said.

It's no secret that Trump has had a fraught relationship with journalists. Even so, Kumar suspects, he'll realize in short time that having press on hand has its benefits.

"It's a two-way relationship. The press serves as the president's vehicle to the public," she says. "If something were to happen to the president, or he did something on his time-out that he wanted the world to know about, they'd say, 'Where's the press?'"

The protective pool usually maintains some distance. If a president is attending church, the pool might wait at a "hold" location, such as a café a block away.

What about the instant information era?

Thomma, whose career covering presidents began in 1987, under Ronald Reagan, says the Trump administration might just be going through growing pains. He is reluctant to fully condemn Trump in his first two weeks of transition, noting every new administration tends to try pushing the press further away.

The White House press corps is going to be nostalgic for Barack Obama, but I was there when we went to war with how [his administration] was dealing with the press. - Steven Thomma , senior White House correspondent

"The White House press corps is going to be nostalgic for Barack Obama, but I was there when we went to war with how [his administration] was dealing with the press."

Less sympathetic to the pool's demands is former White House press secretary Mike McCurry, who served former president Bill Clinton from 1994 to 1998.

"A completely useless device," McCurry says of the pool tradition.

In the instant information age, McCurry sees little purpose for a dedicated pool. Were a national crisis to strike, he says, "senior White House aides would be able to tweet out information faster than a pool can assemble."

But Walsh argues the prospect of that kind of "curated" information is precisely why the pool is needed.

"No one wants to think that the government would lie to its people," she says.

But the press corps exists to give an unfettered perspective and "to make sure the public is still receiving information that's not just regurgitated from the government."