To get Mexico to pay for it, “when the wall arrives at the southern border, we shut the lights; we pretend we’re not home,” Mr. Stewart said. “It’s C.O.D.; Mexico has to sign for it.”

He also announced: “America now finally has an official language. The new official language of the United States is” baloney. (Mr. Stewart used a far stronger word beginning with “b.”)

Mr. Stewart then read a third executive order of greater length:

I, Donald J. Trump, am exhausting. It has been 11 days, Stephen. 11 [expletive] days. Eleven. The presidency is supposed to age the president, not the public. The reason that I, Donald J. Trump, am exhausting is that every instinct and fiber of my pathological self-regard calls me to abuse of power. I want — no, deserve — not just your respect but your adoration. Parades with the tanks and the synchronized dancing, and why can’t they train 10,000 doves to spell out “Trump” in the clouds? How hard can it be? They’re already flying. I, Donald J. Trump, am exhausting because it is going to take relentless stamina, vigilance and every institutional check and balance this great country can muster to keep me, Donald J. Trump, from going full Palpatine, with the lightning coming out of the fingertips and “fear leads to anger, anger leads to hate.” We have never faced this before. Purposeful, vindictive chaos. But perhaps therein lies the saving grace of my, Donald J. Trump’s, presidency. No one action will be adequate. All actions will be necessary. And if we do not allow Donald Trump to exhaust our fight and somehow come through this presidency calamity-less and constitutionally partially intact, then I, Donald J. Trump, will have demonstrated the greatness of America. Just not the way I thought I was gonna.

Mr. Stewart’s appearance at the Ed Sullivan Theater was the latest of the rare visits he has made to this or any other television program since stepping down at “The Daily Show,” the Comedy Central news satire he hosted from 1999 to 2015. (That is also where Mr. Colbert first broke through, as a supremely arch correspondent, before going on to host “The Colbert Report.”)