(CNN) For President Donald Trump's ever-evolving communications staff, the fickle force that drives their days often appears in a tweet. The subject matter might be difficult to predict, but the means by which it arrives can feel as certain as the very early rising sun.

On Thursday, the President rose to criticize Congress, tout the stock market, deny he called the White House "a dump," complain about Russia relations and promise a surprise in West Virginia. It was, in context, a calm morning.

Confronted with more roiling declarations during past briefings, former press secretary Sean Spicer offered, over and again, his now famous dodge: "The president's tweet speaks for itself."

The phrasing might have varied, but the structure never wavered. Confronted with Trump's March 4 claim that President Barack Obama "tapped" Trump Tower before the 2016 election, Spicer effectively forfeited the point, saying, "I'm just going to let the tweet speak for itself." When Trump doubled down, Spicer, in his own way, followed suit. "I think the president's tweets stand for themselves," he said.

The most consequential and instructive phrases in political life are rarely the product of focus groups or high-level strategic skull sessions. Many are forged in the moment, products of necessity -- to drive home a crucial message or beat back an existential threat. The Trump administration is still young. We don't yet know which words will define it because we don't know how these stories end. What's clear so far, though, is that this White House, for all the bluster, can be as interesting for what it does say as what it holds back.

"People use bureaucratic language to hide what is going on and sort of downplay things," said Dr. Jennifer Mercieca, an expert on political discourse at Texas A&M University. "It's representative of what happened and so something like 'the tweet speaks for itself' is synecdochal. It's the part that stands for the whole, meaning in this case that the White House communications staff doesn't speak for the White House -- Twitter speaks for the White House. Trump's Twitter speaks for Trump."

'Operative' and 'inoperative' statements

The Nixon administration knew a thing or two about a president whose words needed parsing.

Soon after five men, including one with ties to President Richard Nixon's reelection campaign, were arrested inside Democratic Party headquarters at the Watergate office complex in June 1972, White House press secretary Ron Ziegler dismissed their actions, and the story, as a "third-rate burglary."

A little more than two years later, the full breadth of the plot revealed, Nixon resigned.

Ziegler's comments to the press, as he sought to parry damaging revelations along the way, are now part of the canon of political dissembling. As the walls closed in on Nixon, language did the same to the President's chief spokesman.

A year before Nixon left office, and just after he first suggested that White House officials might have played a role, Ziegler offered his most tortured pivot.

''The President refers to the fact that there is new material," he said of Nixon's reversal, "therefore, this is the operative statement. The others are inoperative.''

Asked in 1973, following the resignations of top White House officials, if he owed the Washington Post an apology for denying, and often smearing, their reports and reporters, Ziegler strained and waffled.

"I think we would all have to say, and I would be, I think, remiss if I did not say, that mistakes were made during this period in terms of comments that were made," he replied. "Perhaps."

Ziegler was duly honored for this contortion, in 1974, by The Committee on Public Doublespeak at its first "Doublespeak Awards."

Now, more than four decades on, Ziegler's prolific catalog of lies, half-truths and deflections remain a seemingly unconquerable standard. (At least among political communications professionals.) He was, in a sense, the perfect press secretary for Richard Nixon.

Who said "malaise"?

Sloganeering is a fundamental political practice.

Many candidates and parties drill down on their priorities, hoping to mine a deliverable message to the voting public. This can be a trying and expensive process, often costing millions in consultants' fees. But not always. Some, like Trump, give their message a whirl on Twitter, slap it on a hat and ride the wave.

And then there are cases like former President Jimmy Carter's.

"Sometimes phrases are created inadvertently," said Tim Naftali, a CNN presidential historian who teaches at NYU. "For example, I don't believe that Jimmy Carter really thought to have a speech known as the "malaise speech." Indeed, Carter never used the word, even as he lamented "a crisis of confidence ... that strikes at the very heart and soul and spirit of our national will."

"Now, to people of a certain generation, if you use the word malaise, they'll start talking about Jimmy Carter and his ugly sweater," Naftali said. "So you have these successful efforts to create a catch phrase and these unintended and therefore unsuccessful efforts."

Carter might have misplayed his politics, but he was acting under immense pressure. In his case, it was an energy crisis. The most enduring flubs are typically spoken under the klieg lights, when a politician (or spokesperson) gets caught between the facts and their past statements.

Few have blundered more jarringly than President Bill Clinton, as he gave testimony to a grand jury during the Lewinsky scandal. Asked whether his lawyer had lied on his behalf in denying outright any sexual relationship between the president and the intern, Clinton jumped down a legalistic rabbit hole.

"It depends on what the meaning of the word 'is' is," he replied, attempting to confuse a blunt truth with eye-rolling pedantry. The sentence stuck because, as Mercieca explained, it became "the part that stands for the whole." On this issue, Clinton simply could not be trusted.

"The phrases that persist or survive ... are emblematic of the administration, that gives you a sense of the spirit of the place, of the White House and the President," Naftali said. "That's why 'The Buck Stops Here' is remembered. Yes, it was the phrase on Truman's desk, but if Truman wasn't known for being decisive then no one would have remembered it."

Proverbs were repurposed

Of all the catchphrases, "mistakes were made" remains the most pervasive. Ziegler, former President Ronald Reagan, and assorted members the George W. Bush administration all either fell back on it, or put its passive powers to active use. Ironically, the theory behind it transcends culture and nationalism.

"The Soviet Russian used the passive voice all the time," Naftali said. "It was a way of protecting yourself. If you use the passive voice, it's never who's the actor in the phrase. And more than occasionally, politicians are not profiles in courage. The passive voice is a wonderful refuge for them."

When Bush's attorney general, Alberto Gonzales, came under pressure to explain why eight US attorneys had been fired for political reasons, as new documentation then suggested, he reached back for the old chestnut.

"I acknowledge that mistakes were made here," he said. "I accept that responsibility." (He resigned six months later.)

A decade earlier, Reagan too reached for the phrase when he was grappling with the Iran-Contra affair. After first conceding, if hazily, his role in the arms-for-hostages scandal, Reagan in his 1987 "State of the Union" speech offered that "serious mistakes were made." He then quickly pushed on to a riff about the danger of becoming "so obsessed with failure that we refused to take risks that could further the cause of peace and freedom."

Reagan's rhetorical efforts in service of winding down the Cold War were more successful. He frequently used a translation of the Russian proverb, "Doveryai no proveryai," commonly known (and used now by politicians of all stripes) as, "Trust, but verify," as a means of selling his decisions.

The phrase, though old, was resonant because it neatly registered the unique challenges of the moment.

"In the context of détente and the end of the Cold War," Mercieca said, "the question then was how do you learn to trust your enemy, when they've been your enemy for 50 years and we know, specifically, we are not supposed to trust them."