Far be it from me to defend what Jon Stewart has demolished.

But I would like to speak up on behalf of the fledgling New York mayor’s de Blasphemy, now universally deemed his first mistake and possibly grounds for impeachment: daintily carving up his smoked-mozzarella-and-sausage pizza at Goodfellas in Staten Island with a knife and fork.

I’m not saying it’s right. I know it’s wrong. I’m just saying I do it, too. I eat pizza with a knife and fork because I want only the gooey stuff on top, not the crust.

(When I first started in The Times’s Washington bureau, I soothed my nerves by noshing on pizzas slathered with mashed potatoes, a dish that required a spoon and bigger jeans.)I almost didn’t become a Times columnist because of a de Blasio-like faux pas. When Arthur Sulzberger Jr. took me to breakfast to discuss the possibility of a column, we were talking when he suddenly looked dismayed. I thought it was my ZERO knowledge about NATO, but it wasn’t.

“Why,” he asked me, “are you eating your muffin with a knife and fork?”

I thought I was being ladylike, which might have been de Blasio’s problem as well. The photos looked way too ladylike for the 6-foot-5 mayor. It seemed more like the prissy move of Warren Wilhelm Jr. of Cambridge — his original name which he changed because of his estrangement from his alcoholic father — than the paesano Bill de Blasio of Brooklyn.

Fearing my future depended on it, I immediately clutched the muffin. But switching to your hands midway, as the mayor also did, simply makes you seem feckless as well as forkless; better to stick to your guns, and tines.

David Letterman’s Top Ten “Odd Habits of Mayor Bill de Blasio” on Monday featured this one: “Refers to himself as ‘Her Majesty.’ ”Indeed, when F.D.R. served King George VI and his wife, Queen Elizabeth, their first hot dogs on a 1939 visit to America, the confused queen ate hers with a knife and fork, afraid to heed the president’s advice to pick it up and relish it.

Pizza can be hazardous to an administration. We all remember what happened when a Clinton intern delivered a pie to the Oval Office during a government shutdown.

But de Blasio’s offense was so trivial that the most irritating part was the labor-loving mayor’s labored explanation, grandly attributing it to “my ancestral homeland.”

“I have been in Italy a lot, and I picked up the habit for certain types of pizza,” he told reporters. “So when you have a pizza like this, it had a lot on it, I often start with a knife and fork but then I cross over to the American approach and pick it up when I go farther into the pizza. It’s a very complicated approach, but I like it.”

He sounded like a parody of the self-serious New York liberal, convinced he’s right about everything from the Sandinistas to stop-and-frisk to a slice in Staten Island.

De Blasio sounded alarmingly like Zosia Mamet’s mega-rambling character, fellow Brooklynite Shoshanna Shapiro, on a recent “Girls,” when she quizzes a quizzical Adam about his favorite utensil.

When he says, “I guess a fork,” she lectures: “O.K., that is crazy. Like, why would you want a cold metal prong stabbing you in the tongue when instead you could have food delivered into your mouth on, like, a cool, soft, pillowy cloud?”

The new mayor should have just laughed it off. Then he might not have ended up getting reduced to rubble by Jon Stewart, who asked “the champion of the middle class”: “Were you elected the mayor of Italy? No! Look out the window of the pizzeria. ... Do you see a Sistine Chapel or a Leaning Tower of Pisa? No, you don’t! You see several junkyards and a tanning salon.”

Unlike de Blasio, some pols use food as a way to seem more populist. The aristocratic Poppy Bush pretended his favorite snack was pork rinds, offsetting his request for “just a splash” more coffee at a New Hampshire truck-stop diner.

As with Christie the Bully, embarrassing incidents hurt politicians when they resonate about a deeper suspicion.

Sargent Shriver calling for a Courvoisier in an Ohio mill town bar. Jerry Ford at the Alamo, biting into a tamale without removing the corn husk. Jimmy Carter’s fishing trip that turned into “Paws,” fending off a Killer Rabbit. Michael Dukakis advising farmers to grow Belgian endive, and Barack Obama talking the price of arugula. When John Kerry ordered Swiss cheese on his Philly cheesesteak in 2003, it buoyed Republican efforts to paint him as a Frenchie, fromage-loving surrender monkey.

“The whiff of a limousine-liberal factor,” G.O.P. strategist Mike Murphy told me, does not hurt de Blasio because he comes off as such “a humble, likable guy. He lacks the firing-squad instinct that makes for a true Commie leader.”

The question lurking beneath the surface with de Blasio is: Has he been promoted out of his league?

The answer can’t be determined when he devours his Staten Island pizza as though he were at the Tower of Pisa.