There is no such danger in Mr. Trump’s safe space. But it also means he’s not reaching anyone beyond his base — a strategy that, the Republican drubbing in the off-year elections suggests, has its limits.

For his die-hard fans, Mr. Trump sticks to his greatest hits: the media is “fake” (“one of the greatest terms of all I’ve come up with,” he told Mr. Huckabee); we’re going to build the wall; they said we couldn’t get to 270 electoral votes, but we got 306. (Ultimately 304.) He’s speaking to an audience that isn’t watching to see news made or questions answered but to hear, again: We won.

Indeed, Mr. Trump’s interviews with his boosters hardly make news except by accident, as when he defended a lag in diplomatic hiring to Ms. Ingraham by saying, “I’m the only one that matters.”

To understand Mr. Trump as a president, you have to remember that he was a celebrity first, and he still uses the media like a celebrity does. His first remark to Ms. Ingraham about the Republican tax bill was “We’ve gotten really great reviews,” as if he were plugging a new movie on “The Tonight Show.” He repeatedly gave Mr. Hannity his highest honor: praising his Nielsen ratings.

In Mr. Trump’s first celebrity phase, as a brass-plated capitalist cartoon in the ’80s and ’90s, he was a media gadfly. He chased the cameras, planted his name in the tabloids and exchanged locker-room talk with Howard Stern. The point, then, was to be outrageous, to stir the pot. There was no such thing as bad attention.

This was the approach that the candidate Trump used, keeping CNN and “Morning Joe” on speed dial, taking advantage of billions of dollars of free media to ensure that he was the protagonist of the election. For a while, in 2015 and 2016, he was freely available on TV, proving that he could shoot off his mouth in a Fifth Avenue studio and still not lose his voters.