Did you hear the one about Donald Trump?

Has there ever been a president as humorless as Donald Trump? Doubtful. Trump traffics in bombast, braggadocio and bluntness. He is a master of insults, self-praise, and mangled syntax. But he is no John F. Kennedy or Ronald Reagan — both presidents who were masters of the well-aimed witticism. The current occupant of the Oval Office is only funny unintentionally. He is a joke, but he doesn’t make jokes.

Recall his remarks at the Alfred E. Smith Memorial Foundation Dinner in New York on Oct. 20, 2016. These events are supposed to be a time for political leaders to be light-hearted and to poke fun at themselves. Trump barely managed to get off a couple of ghostwritten one-liners before veering into a cringe-inducing denunciation of his opponent, Hillary Clinton, who was sitting right behind him. He went on to accuse Clinton (inaccurately) of being “so corrupt, she got kicked off the Watergate Commission,” of being hypocritical (“Hillary believes that it’s vital to deceive the people by having one public policy and a totally different policy in private”) and, finally, of “pretending not to hate Catholics.” The audience reacted with boos rather than the more typical laughs.

Yet if you listen to Trump defenders, you would think that he is the Marx Brothers, Mel Brooks, Chris Rock, Amy Schumer and Aziz Ansari, all wrapped up into one rolling-on-the-floor package of hilarity.

Last week, Trump thanked Vladimir Putin for expelling 755 personnel from the U.S. Embassy in Moscow — “I’m very thankful that he let go of a large number of people because now we have a smaller payroll,” the president said. Most observers interpreted this as further evidence of Trump’s toadying to the Russian dictator, who helped him win the presidency. But Rep. Ron DeSantis (R-Fla.) claimed to detect wit of a high order. Trump, he said, was speaking “tongue-in-cheek.”

This brand of lame excuse has actually become the go-to explanation for Trump’s outrageous remarks. As noted by CNN and the Huffington Post, among others, the president’s apologists often detect unsuspected humor in his offensive and inane comments.

In July, for example, Trump endorsed police brutality, telling a convention of cops “please don’t be too nice” when throwing suspects “into the back of a paddy wagon.” There was not a trace of a smile on his face as he spoke, nor did anyone laugh (although, disturbingly, a lot of the audience applauded). The next day, as police departments across the country condemned the president’s remarks, White House Press Secretary Sarah Huckabee Sanders offered this defense: “I believe he was making a joke.”

A year earlier, in July 2016, Trump told the press he hoped Russia would hack and release private emails from Hillary Clinton’s private server: “Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing,” Trump said. White House Press Secretary Sean Spicer later claimed, “He was joking at the time. We all know that.” We do?

Trump’s humor apparently extended to telling then-FBI Director James Comey to stop investigating fired National Security Advisor Michael Flynn. Comey testified to Congress under oath that the president told him: “I hope you can see your way clear to letting this go, to letting Flynn go. He’s a good guy. I hope you can let this go.” Rep. James Comer (R-Ky.), a member of the House Oversight Committee, tried to excuse what looks very much like obstruction of justice by claiming that Trump was just kidding — “it looks different on paper.” The punchline, of course, was that Trump fired Comey for ignoring his instructions.

Trump himself has embraced the “I was joshing” defense. In August 2016 he claimed that President Obama was “the founder of ISIS,” and refused to back down when questioned about that ludicrous claim by radio host Hugh Hewitt. But later Trump explained that he had been kidding. So, too, in January 2016 he claimed was just kidding when he said that global warming was a Chinese hoax — a claim he had first made in 2012 and repeated many times without a hint of levity.

Trump also hides behind the cloak of humor when demeaning those around him. At a lunch with the Security Council, Trump solicited views of his U.N. Ambassador Nikki Haley: “Does everybody like Nikki? Otherwise she can easily be replaced.” Ha ha, from a man notorious for actually firing aides right and left.

This “kidding/not kidding” routine is a way for Trump to preserve a shred of plausible deniability and for his spokesmen to walk away from his crazier comments. But if you think Trump isn’t being serious, the joke’s on you. Trump would actually be a little easier to take if he had a modicum of wit. But he doesn’t. He’s about as funny as that notorious cutup Calvin Coolidge.