Barack Obama’s swan song as Comedian-in-Chief—scheduled for Saturday night at the White House Correspondents Association Dinner—will doubtless display his natural comic timing and pointed wit that are rare for any politician, let alone the head of state of the planet’s only superpower.

Obama’s appearance at the eighth such dinner of his presidency—in which he’ll be expected to aim jokes at Donald Trump, Paul Ryan, Mitch McConnell, and possibly even himself, while showing an expertly-produced and amusing video in the basement ballroom of the Washington Hilton—will also represent the apotheosis of a peculiarly American phenomenon.

Over the past five decades—spanning from John F. Kennedy to Ronald Reagan to Bill Clinton to Obama—playing the clown has become part of the presidential job description even if it isn’t an explicit constitutional duty. So presidents show up in late winter and early spring for endless black-tie banquets—roiling with journalists, government officials, pop-culture celebrities and other self-impressed types—and try to make them laugh.

No other nation on earth imposes on its leaders the requirement to be funny—especially not in the ritualized, professionalized fashion of modern, media-savvy presidents who are compelled to amuse their inferiors at the Gridiron, Alfalfa Club, Radio and Television Correspondents and, finally, this particular dinner on Saturday night that caps official Washington’s annual festival of self-celebration.

“The American context is one in which we like to think that our rulers are not that separate from us. We don’t like the distance,” says Texas A&M political science professor George C. Edwards, the editor of Presidential Studies Quarterly. “The idea that you can make fun of somebody and that they will be sitting there while you’re making fun of them, and then they’ll make fun of you, reflects the genuine ethos of American egalitarianism.”

National Journal White House beat reporter George Condon, who’s at work on a definitive history of the 102-year-old correspondents’ association—of which he was president during the first year of Clinton’s administration—agrees.

“It’s in our DNA—that we didn’t have kings and queens, we have regular people as our leaders, and that they come from us,” Condon says. “And to show that you have a sense of humor is just one way of showing that you’re of the people.”

The first president to attend the dinner was Calvin Coolidge in the late 1920s, Condon says. Silent Cal gave a long and droning address about the separation of powers—prompting the association to tell future presidents not to worry about a speech, just to enjoy the show, which eventually featured big bands, comedians, and even Dinah Shore.

The gregarious and fun-loving Franklin Delano Roosevelt immensely enjoyed the dinner, although he schmoozed with reporters instead of performed—and a couple of times gave gravely serious, nationally broadcast talks about the progress of World War II.

FDR attended his last dinner in 1945 shortly before his death. Harry Truman hated the dinner and seldom attended. Ditto Dwight Eisenhower.

JFK was the first president to deliver extended comic speeches, and Lyndon John enlisted Bob Hope and future Jaws novelist Peter Benchley to feed him material.

Richard Nixon had little use for the correspondents association and in 1973, as the Watergate scandal blossomed and he was forced to sit on the dais with journalists who were on his Enemies List, he opened with: “It is a privilege to be here at the White House correspondents dinner. I suppose I should say it is an executive privilege”—a stilted reference to the bogus legal theory the Nixon White House was claiming to avoid handing over incriminating material in the ongoing investigations.

Gerald Ford enjoyed the camaraderie of the dinner both years of his brief presidency, but Jimmy Carter resented that, as he wrote in his diary, he was being forced to sing for his supper and endure face-time with ink-stained wretches who spent the rest of the year attacking and belittling him.

Reagan, a Hollywood denizen who in 1954 emceed a variety show in Las Vegas, was a member of the Friars Club, and later, as governor of California, appeared on several Dean Martin Roasts, was a natural performer who loved having an audience. He was self-deprecating, and he killed. George H.W. Bush, not so much.

Condon tells me Bush 41 was thrilled in 1989 when Garry Shandling agreed on the spur of the moment to help him with his routine. (Obama, meanwhile, will be followed to the microphone by Comedy Central host Larry Wilmore.)

Clinton, who recruited the services of the pre-senatorial Al Franken and Everybody Loves Raymond showrunner Phil Rosenthal, among other comedy pros, was the first president to show videos at the dinner. His final performance in 2000 was graced by a memorable short film in which he was depicted as a lame-duck chief executive with barely anything to do while his vice president, Al Gore, ran for president and his wife campaigned for a New York Senate seat.

Clinton was shown washing the presidential limo, mowing the South Lawn, playing Battleship in the Situation Room with the chairman of the Joint Chiefs, riding a bicycle with his friend Terry McAuliffe up and down the corridors of Old Executive Office Building, and running after Hillary’s car with the bagged lunch she had forgotten to take with her.

It was, for Clinton, an unusual instance of making fun of himself—and the crowd at the Hilton roared.

By contrast, it is difficult to imagine that this the sort of tradition would flourish in, say, France (whose quintessential leader, Charles De Gaulle, purposely kept his citizens at bay, believing distance equaled dignity), the People’s Republic of China, Iran, Saudi Arabia, or, for that matter, Turkey—whose authoritarian president, Recep Tayyip Erdogan, regularly jails political jokesters and recently demanded that the government of Germany prosecute a German (!) comedian who had the temerity to mock the Turkish strongman on a German (!!) television program. At last report, the German state prosecutor (!!!) was looking into the possibility.

In Britain, Question Time in the House of Commons provides no shortage of wisecracks lobbed back and forth between the prime minister and his or her loyal opposition, and sharp humor intrudes on the occasional after-dinner speech delivered during a party conference. But the joshing and jesting have yet to achieve the formal, ceremonial status that has become compulsory in the Colonies.

The former Tory Leader William Hague of the late 1990s—later David Cameron’s foreign secretary—was renowned for his ripostes during parliamentary debate, ostensibly a technique for eroding the popularity of the governing Labour Party and then-Prime Minister Tony Blair.

“William thinks that humour is a very valuable weapon,” an ally once confided to The Independent. “The important thing about political jokes is not that they are funny in themselves but that they tell a political truth.”

But while Hague’s fleet-footed japes were applauded in the media, he couldn’t avoid the fact that they never helped him fulfill his ambition to obtain the top job.

“Fat lot of good it did me,” Hague ruefully noted, according to British journalist Phil Dampier, co-author of White House Wit, Wisdom and Wisecracks, a compendium of presidential one-liners.

“Humor is a good way of getting your message across,” Dampier says, noting that London Mayor Boris Johnson, a former journalist who regularly appeared on the popular BBC show, Have I Got News for You?, parlayed his television persona as an affably bumbling buffoon into elected office. “And now he’s being talked about as a possible prime minister,” Dampier says.

On the other hand, when Queen Elizabeth’s adult children, led by Prince Edward, ventured into slapstick comedy in 1987—dressing up as giant vegetables and hurling fake hams at each other and various celebrities to raise money for charity in a television special titled It’s A Royal Knockout—the spectacle was widely considered “a PR disaster,” Dampier says, “and seen as a real low point, a cheapening of the monarchy.”

The queen, at least, had the good sense not to participate in a farce that would have been a laugh too far even for an American president.

Indeed, University of Minnesota political scientist Lawrence R. Jacobs warns that excessive or misguided joking by a president could ring hollow and harm the office.

“The idea of presidents who wield this enormous and increasingly unaccountable power ‘having a laugh’?” Jacobs says. “Not so funny.”

An especially piquant example occurred at the Radio TV Correspondents dinner in April 2004, when George W. Bush did shtick about the U.S. military not being able to locate Saddam Hussein’s apparently nonexistent weapons of mass destruction—the stated rationale for going to war in Iraq

“Those weapons of mass destruction have to got to be somewhere,” Bush joked while an antic slide show played, showing him searching under furniture in the Oval Office. “Nope, no weapons over there… maybe under here?”

The public outrage was immediate concerning Bush’s attempt to find humor in an ill-advised military adventure that had resulted in thousands of Americans and Iraqis dead and wounded.

“There are lines you cannot cross,” Clinton White House joke-writer Mark Katz, an occasional contributor to The Daily Beast, told CNN at the time. “With regard to going to war, sending American troops to war to find weapons of mass destruction, that’s a joke that’s playing out on the world stage—and is at our expense.”

Meanwhile, Jacobs, a regular at comedy clubs in Minneapolis and New York, claims that Obama’s standup routines tend to be pugnacious rather than hilarious.

“His humor has always struck me as painful in the sense that it was less the joshing around where we’re all letting our hair down here, and more about settling scores,” Jacobs says.

Jacobs, for instance, didn’t appreciate Obama’s famous and widely praised (including by this reporter) evisceration of Donald Trump—who at the time, on May 1, 2011, was not the Republican presidential frontrunner but simply a reality show billionaire and rabid birther who’d been loudly questioning the legitimacy of the president’s Hawaiian birth certificate.

“Donald Trump is here tonight!” Obama announced to the 3,000-odd dinner-goers in the Hilton ballroom, including Donald and Melania at The Washington Post table. “I know that he’s taken some flak lately. But no one is happier, no one is prouder, to put this birth certificate matter to rest than The Donald. And that’s because he can finally get back to focusing on the issues that matter—like, did we fake the moon landing? What really happened in Roswell? And where are Biggie and Tupac?”

Trump’s smile stiffened as Obama continued, “All kidding aside, obviously we know about your credentials and breadth of experience.” At this, ripples of laughter coursed through the crowd. “For example—seriously—in an episode of Celebrity Apprentice, at the steak house, the men’s cooking team did not impress the judges from Omaha Steaks. And there was a lot of blame to go around. But you, Mr. Trump, recognized that the real problem was a lack of leadership. And so ultimately you didn’t blame Lil John or Meatloaf. You fired Gary Busey. And these are the kinds of decisions that would keep me up at night.”

The Trumps fled the ballroom that night, and the next day, Navy Seals killed Osama bin Laden. Judd Apatow later claimed credit for writing those Trump jokes for the president—one of a team of comedy professionals, including Daily Show writer Kevin Bleyer, who regularly have contributed to Obama’s standup routine.

“Trump had it coming to him,” Jacobs concedes, “but that’s the whole point: The president isn’t there to use humor to get even. That was just him decimating Trump. To me, that’s not humorous. That’s abuse.”

Standup comic Wayne Federman, Jimmy Fallon’s former head monologue writer, has a more generous assessment of President Obama’s comedy stylings.

“I think he’s right up there with Reagan and John Kennedy as far as being a president who can use humor to his advantage,” Federman says. “I just hope that, as usual, he’s funny, that he’s warm and reflective about his eight years in office.”

In a shout-out to his fellow professional, Federman adds: “And I’m rooting for Larry Wilmore to do a good job.”