At an event with Japanese officials at the White House yesterday. Donald Trump took a few moments to reflect on his public standing – which the president believes is amazing.

“[The impeachment process] is a scam. And the people are wise to it. And that’s why my polls went up, I think they said, 17 points in the last two or three days. I’ve never had that one. I’ve never had that one.”

Trump’s approach to polling has long been bizarre. It tends to involve the president picking a number he likes out of thin air, pretending it’s real, and insisting that everyone accept the made-up number as accurate.

But this latest boast is uniquely ridiculous. A 17-point jump over the course of a few days is practically unheard of – the spike in George W. Bush’s support in the immediate aftermath of 9/11 was a rare exception – and in Trump’s case, it plainly does not exist in reality. Trump’s support has actually fallen as his latest scandal has intensified.

Yes, it’s theoretically possible that the White House has some internal polling that’s telling the president what he wants to hear, but if a significant chunk of the American electorate were suddenly shifting in Trump’s favor, there’d be some indication of it in independent, public polling. No such evidence exists because the Republican made it up.

Making matters worse, real polls show public support for Trump’s impeachment climbing, including a newly released Washington Post-Schar School survey, which found a 58% majority endorsing the impeachment inquiry against the president, while a 49% plurality support removing Trump from office. This is slightly worse than other recent data on the issue and suggests conditions for the president are getting worse, not better.

CNN’s Harry Enten explained late last week that support for Trump’s impeachment is so high at this early stage that it’s “historically unprecedented.”

It’s against this backdrop that the president believes “they” have said his public support has climbed 17 points “in the last two or three days.”

To be sure, Trump has persuaded himself into believing all sorts of nonsense, but there may be a larger significance to this one.

Consider what Americans have seen from their president of late. As the pressure has increased, Trump has unraveled to an unsettling degree, talking up the idea of prosecuting members of Congress who say things he doesn’t like, casually throwing around accusations of “treason,” and raising the prospect of a “Civil War-like fracture.”

But as far as Trump is concerned, people are buying what he’s selling. His public meltdown, in the president’s mind, is a great success, which is being well received by nearly a fifth of the electorate. Trump sees a political landscape in which his popularity is tied to his antics: the more outlandish his posture, the more support he enjoys.

None of this is true, of course, but if the Republican has convinced himself that his claims are correct, it creates a dangerous set of incentives: Trump will be more inclined to act out if he believes Americans are responding favorably to his tantrums.

I shudder to think what he may do next to give himself another imaginary 17-point bump.