Donald Trump is running a top-notch campaign to be a conservative media celebrity.

Unfortunately for him, and especially for the Republican Party, this isn’t the same thing as running a good, or even minimally competent, campaign for president.

From the beginning, Trump has been the candidate by and for the Entertainment Right — the talk-radio hosts, cable personalities and authors who recognize in Trump their own combative style and find it irresistible.

Trump’s campaign has hewed closely to the rules for 21st-century media provocateurs: Always be inflammatory, and never apologize. Wear the media’s outrage as a badge of honor, and attack your critics twice as hard. Repeat as necessary.

Trump didn’t learn these rules as a commentator, but in the world of New York real estate. His dirtball mentor Roy Cohn, the late New York power lawyer, taught him to always stay on the attack and never back down. It was Trump’s discovery that, in the right conditions, the model was transferable to Republican primary politics.

Trump opened a window to his mindset in advice he gave radio talk-show host Howie Carr when Carr was embroiled in a minicontroversy: “Whatever you do, don’t apologize. You never hear me apologize, do you? That’s what killed Jimmy the Greek way back. Remember? He was doing OK till he said he was sorry.”

This isn’t an accurate representation of Jimmy the Greek’s long-ago fall (CBS fired the football analyst almost immediately after his offensive musings about black athletes). But it is telling that this is how Trump remembers it. If only poor Jimmy hadn’t been weak, he might have survived.

Trump’s refusal ever to apologize takes away one way to defuse controversies, and perhaps demonstrate some humanity and humility in the process. So his only options are to double down or try to evade what he said, forcing his defenders to repeat wholly implausible spin.

Believers in the Trump “pivot” are constantly disappointed for a simple reason. Like a good entertainer, Trump always tries to keep his audiences engaged and amused. His campaign is a kind of performance art in which entertainment value is more important than basic political considerations.

While journalists and political strategists are appalled by the distractions, Trump probably looks at things differently. Whenever one of his controversies generates a tsunami of media coverage, he may chafe at how “unfairly” he’s being treated, but part of him must be delighted as a child on Christmas morning at all the coverage.

After his wife’s introduction to the country was spoiled at the Republican convention by a plagiarism controversy, Trump tweeted, “Good news is Melania’s speech got more publicity than any in the history of politics especially if you believe that all press is good press!” And that has, across four decades in the media capital of the world, always been what Trump believed.

Of course, there’s nothing wrong with a deft sense of political theater or boldness. But Trump is pushing the limits of the media-centric candidacy. He isn’t necessarily losing on the issues; he’s losing on demeanor.

In the latest Washington Post/ABC News poll, Trump is roughly even with Hillary Clinton on handling the economy and terrorism, yet he trails badly on every presidential attribute.

So it’s not just a matter of Trump being more focused. He needs to be more dignified, more careful, more respectful and more knowledgeable — in other words, a presidential candidate, not a media celebrity.

He is currently on a path to defeat, although this may bother him less than a typical presidential candidate. In terms of media attention, Trump’s campaign has been, and will continue to be, a runaway success. In his rambling news conference after the GOP convention, Trump bragged about how many Time magazine covers he has had in the past year. There have been reports that Trump is considering starting his own TV network after the election.

And why not? By November, even if he loses, he will be more famous than ever.

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: comments.lowry@nationalreview.com.