A cyclist and Trump's motorcade in Sterling on Saturday. (Brendan Smialowski/AFP/Getty Images)

The departure of President Trump’s motorcade from his Sterling, Va., golf club on Saturday afternoon was chronicled as dutifully and minutely as the retreat of some great army.

The president left Trump National Golf Club at 3:12 p.m. after spending the day there on the edge of the Potomac River.

A thick column of black SUVs escorted Trump past two pedestrians, a Guardian reporter wrote in a pool report — “one of whom gave a thumbs down sign.”

“Then it overtook a female cyclist, wearing a white top and cycling helmet, who responded by giving the middle finger.”

The cyclist was photographed for posterity. So was an “IMPEACH” sign held aloft outside the golf club that day.

On Twitter, Voice of America reporter Steve Herman offered his account as eyewitness to the following events:

“The cyclist flipped off @POTUS a second time when the motorcade halted at the traffic light,” he wrote. “No, we do not know her name.”

Nor does anyone know if Trump, behind bulletproof windows, had seen either of the cyclist’s streetside salutes.

But with knowns and unknowns thus established, the world set about interpreting a middle finger’s significance.

Newsweek wrote, perhaps speculatively, that “to flip off the president of the United States” seemed to be the cyclist’s single-minded goal.

The Guardian avoided analysis. The Reddit commenter zablyzibly did not: “Some heroes wear bike helmets.”

Accused of polluting the record of a motorcade’s passage with details that were not, really, news, Herman defended himself. “The cyclist’s act has certainly generated an emotional reaction among many,” he wrote.

We’ll go him one better. That fleeting, vulgar indignity to the world’s most powerful person was not just news, but a historical tradition.

2001: A man throws an egg at Bill Clinton

Former president Bill Clinton had not been gone from the White House three months when, as ABC News reported, he walked out of an antique store in Poland and was hit on the arm with an egg.

“The former president took off his suit jacket and continued his walk in sunny weather for another 15 minutes, signing autographs and greeting tourists,” the station reported. Meanwhile, security forces wrestled the teenage egger to the ground.

“It was good for young people to be angry about something,” Clinton remarked, his spokeswoman later told reporters.

The Bush years: ducked shoes and flipped birds

The most memorable indignity an American president suffered in the modern era may belong to George W. Bush, whose 2008 news conference at a Baghdad palace was interrupted when an Iraqi TV reporter took his shoes off and flung them at the lectern.

“This is a goodbye kiss from the Iraqi people, dog,” Muntadar al-Zaidi yelled as Bush ducked the first shoe.

“This is for the widows and orphans and all those killed in Iraq,” he yelled as the second shoe followed.

Like Clinton did his egging, Bush took his shoeing in good humor. “It has got to be one of the most weird moments of my presidency,” he later reflected.

He didn’t mention an incident two years earlier, in some ways no less weird.

Bush was riding in his presidential motorcade through Seattle, as Trump would do years later in Sterling. The president amused himself by waving at a fleet of school buses, full of children returning from a field trip to the zoo.

“The president was having a great time. He was waving at everybody, he waved at the kids,” Rep. Dave Reichert (R-Wash.) later recounted, according to the Associated Press.

“The sad part of it is though, we got to the last bus — and I won’t tell you which school district this was — the bus driver flipped the president off.”

Reporters soon found out the name of the school district. Despite protesting that only the president — not the children — had seen her middle finger, the bus driver was fired.

President Obama and the comforts of heckling

While speaking about the closing of Guantanamo Bay at National Defense University, a heckler interrupted President Obama's speech and he addressed her directly. (The Washington Post)

A few months into his presidency, Barack Obama addressed Congress, wagging his finger at U.S. senators and representatives as he spoke of his plans for immigration reform.

“The reforms I am proposing would not apply to those who are here illegally,” Obama told Congress.

“You lie,” Rep. Joe Wilson (R-S.C.) yelled from his seat.

“Oooooh!” exclaimed a chorus.

“It’s not true,” Obama said, and went on with his speech.

If the 44th president lacked for projectiles and obscenities, hecklers balanced out the deficit — so many hecklers that in Obama's second term he told an audience of college students, “I wouldn't feel comfortable if I didn't have at least one.”

Maybe Obama took solace in tradition. The Washington Post once traced the history presidential heckling as far back as Abraham Lincoln, who on the day before his Gettysburg Address remarked to a less-well-remembered crowd:

“In my position, it is somewhat important that I should not say any foolish things.”

And heard back this: “If you can help it.”

A century and a half later, President Trump may be less sanguine about mockery.

We don’t know if he saw the bird flip on Saturday, or what he thought of it if he did. But Trump has faced no end of jeerers at his rallies and has often shared his feelings with the crowd.

“I’d like to punch him in the face,” he said last year, for example.

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