The rule with Trump is simple: the closer you look, the less there is. Photograph by Charlie Neibergall / AP

With just more than a week to go until the first televised Republican debate, Donald Trump remains the center of attention. On Monday, the Daily Beast dredged up an old story about his ex-wife, Ivana, accusing him of forcing her to have non-consensual sex. (Ivana Trump has issued a statement calling the story "totally without merit.") What grabbed the attention of campaign watchers wasn’t so much the allegation itself, which was made during the Trumps’ acrimonious divorce case, twenty-odd years ago, but a statement to The Daily Beast by one of Donald Trump’s top lawyers, Michael Cohen, who said, “You cannot rape your spouse.”

In fact, marital rape is a crime in all fifty states. What impact this latest verbal outrage from the Trump camp will have on his support among Republicans remains to be seen. According to one school of thought, which views his popularity partly as a product of the mainstream-media attacks on him, the flap could conceivably help him. I doubt it. Sooner or later, Trump’s act will start to seem old, even to G.O.P. voters. And that moment might well arrive sooner than expected.

I say this as someone who has observed Trump’s career for more than twenty-five years, and who warned six weeks ago of his capacity to cause trouble for the Republicans. Nobody should underestimate Trump’s ability to manipulate the media, or his willingness to do or say anything to further his goals and draw attention to himself. In racing to the head of the G.O.P. polls, he has displayed these talents to the fullest. Underneath it all, though, he’s the same carnival barker that New Yorkers have had to put up with for decades: an aptly named tub of hot air, whose noisy and odiferous utterances rarely withstand serious scrutiny. (My colleague Amy Davidson demonstrates as much in the magazine this week.)

The rule with Trump is simple: the closer you look, the less there is. Less money, less substance, less meaning. For a consumer brand attached to condominiums, golf courses, and reality-TV shows, having a well-earned reputation for exaggerating isn’t necessarily a big problem. The name Trump denotes ostentatiousness: overselling the product is almost part of the appeal. And, in any case, with most of Trump’s ventures he is just the front man: others do the actual work of satisfying the customers.

A Presidential candidacy is different. After the first burst of publicity, it turns into a fraught, extended exercise in withstanding attacks and critical examinations. This has never been Trump’s forte. When challenged in the past, he has often resorted to sliming his critics or stomping off. In his off-color comments about Rick Perry and John McCain, we have already seen the first of these tactics being repeated. As the level of media scrutiny increases, we could well see him look for cover.

The Daily Beast story was the latest indication of what lies ahead. For weeks after Trump entered the race, cable networks treated him as a novelty candidate (and a ratings boost from the gods), according him practically unlimited airtime to say whatever he wanted. Now, finally, some broadcast journalists are starting to ask Trump awkward questions. This weekend, for example, CNN’s Jake Tapper pressed him on how he would deal with illegal immigrants—an issue he has placed front and center in his campaign.

As Rob Garver, of the Fiscal Times, pointed out in a brutal post, Trump’s responses amounted to “a sort of immigration-related word salad.” “We have some really bad dudes right here in this country and we’re getting them out. We’re sending them back where they came from,” Trump said, then went on, “The bad ones are going to get out. Then, from that point on, we’re going to look very, very strongly at what we do. And I’m going to formulate a plan that I think people are going to be happy with.”

Tapper tried repeatedly to elicit some details, pressing Trump, for instance, on the millions of undocumented immigrants without criminal records who would remain. All he got back was verbiage. “We’re going to see what we’re going to see,” Trump said. He added, “We’re going to take the high ground: we’re going to do what’s right. Some are going to have to go, and some—hey, we’re just going to see what happens. It’s a very, very big subject, and a very complicated subject.”

So it is, and that’s one reason why Trump’s rivals for the Republican nomination have struggled to compete with his inflammatory statements. Even in today’s G.O.P., though, rabble-rousing takes you only so far. As time goes on, he will face more questions about his evasions and exaggerations, and the vacuity of his rhetoric will be increasingly difficult to ignore.

To take another example, we have Trump’s claim, two weeks ago, that he is worth more than ten billion dollars. In my experience dealing with his more outlandish estimates of his own wealth, a useful, if not entirely reliable, rule of thumb is to move the decimal point one place to the left. That would place his net worth at about a billion dollars, which is actually pretty close to the $1.15 billion figure cited as his minimum net worth in an analysis, by Tim Mullaney of CNBC, of a financial-disclosure form released by the Federal Election Commission last week. (Because most of Trump’s companies are private, any net-worth figure is only an estimate. Forbes reckons he is worth about four billion dollars; Bloomberg says around three billion.)

CNBC also questioned the valuation of Trump’s golf businesses at between five hundred and fifty million dollars and more than six hundred seventy-five million dollars. When Mullaney took a closer look, he found that Trump was valuing his golf courses, some of which are well known, at somewhere between two and four times the revenue they generate, whereas most people in the golf industry use a multiplier of one to one and a half times a course’s revenue. “Stacking it up against the universe of other golf-course sales, he is kind of off the charts,” Buddie Johnson, an Arizona-based course developer who wrote a book about valuing golf courses, told Mullaney. “Anyone can say anything. ... Such is his verbosity that, when he talks about the valuation of his golf clubs, he talks louder than anyone else, and he thinks that makes it true.”

Mullaney’s story didn’t garner a great deal of attention, but it displayed the sort of scrutiny that Trump hates. Back in 2005, Timothy L. O’Brien, a former Times reporter who is now the publisher of Bloomberg View, wrote a book about Trump in which he cited reports estimating his net worth at well under a billion dollars. Months later, Trump sued O’Brien—for five billion dollars. (The case was dismissed. Last week, O’Brien recalled the episode in a column entitled “Dear Mr. Trump: I’m Worth $10 Billion, Too.”)

At some point, Trump will have a choice to make. Does he try to shake off the media intrusions, hire some credible policy advisers, and put together some semi-serious proposals, backed up by actual facts? There’s been speculation that he could even run in the general election as an independent or third-party candidate, as George Wallace did, in 1968; as John Anderson did, in 1980; and as Ross Perot did, in 1992 and 1996. But does Trump have the conviction of a Wallace, the bravery of an Anderson (who broke with Richard Nixon and Ronald Reagan), or the rigor of a Perot? Merely to pose the question is to answer it.

Another option would be to call off his campaign, retreat to Trump Tower, and seek to monetize his enhanced name recognition. Perhaps I’ll be proved wrong, but I suspect that, sometime between now and the Iowa caucus, Trump will choose the latter route.

* This post has been altered to include Ivana Trump's statement on the Daily Beast story and to further detail CNBC's analysis of Donald Trump's net worth.