Over the course of American history there have been great presidents, terrible presidents, and many in between. But here's a prediction: Even if Donald Trump is defeated soundly in 2020 and leaves office with record-low approval ratings, leaving behind him a trail of scandals and an agenda in tatters, he'll say to anyone who'll listen, "I was the most amazing president ever. Except for maybe Abe Lincoln, but maybe not. That went so terrific, believe me."

Will he believe it himself? It's hard to tell what lurks in Trump's brain. But so far, he seems to believe that he's absolutely knocking this presidenting thing out the park.

"Never has there been a president, with few exceptions — case of FDR, he had a major depression to handle — who has passed more legislation and who has done more things than what we've done," he said a few weeks ago, despite the fact that he has not signed a single significant piece of legislation. Every president and every White House engages in spin, of course — they express limitless optimism that success will be theirs once everyone realizes the wisdom of their plans and the purity of their intentions. But Trump has raised spin to an entirely different level, creating a world where everything he does is a smashing success, no matter how dissatisfied the public is and how little he manages to get done.

This goes way back for Trump, to long before he was a politician. As a boy, his parents took him and his siblings to services at the church where Norman Vincent Peale preached, so he could imbibe Peale's teachings on turning thought into reality. The author of The Power of Positive Thinking told his flock and his readers that anything is possible with a sufficiently enthusiastic self-confidence.

Throughout his business career, Trump applied Peale's lessons to real estate, figuring out how to use the image of wealth to create wealth. He carefully cultivated the New York media and crafted an over-the-top persona meant to embody money and success. The wider the image was spread, the more people who would lend him money for real estate projects, buy his apartments, or stock up on Trump steaks and Trump mattresses. The image of success could thus be transubstantiated into the reality of success, even if the place it started from was as thin as the gold paint in his penthouse.

He continued to apply this lesson when he ran for president. Again and again, Trump would come before a rally and say that the crowd in front of him was the biggest the venue had ever seen, and there were thousands of people outside waiting to get in; journalists would dutifully report that in fact there were some empty seats and no one was waiting outside except protesters, but Trump's supporters didn't seem to care. From the moment he began he acted like he was winning whether he was or not, and somehow by the end it turned into reality.

All of which served as yet more evidence for him that the strategy is foolproof. Which means that no defeat, no setback, no screwup could lead Trump to think about what he had done wrong or what kinds of adjustments might be made. The answer is always simple: Keep telling everyone how great you're doing, and everything will turn around in your favor.

Which might happen. But in the meantime, things are not going well. Trump's approval ratings are in the 30s. His White House is riven by backstabbing and infighting, with unprecedented levels of leaking as the various factions try to position themselves as not responsible for the mess being made. As for the top item on the GOP legislative agenda, though Trump promised that the Republican health-care plan would deliver "something terrific," in fact it is nothing less than the most unpopular piece of legislation in the history of polling. Trump's withdrawal from international agreements on climate and trade has led other countries to decide to go ahead and craft a new international order without us. America's image in the world has plummeted; a recent Pew Research Center poll of 37 countries found that in 35, people expressed less confidence in Trump's decisions than they had in President Obama's (Israel and Russia were the exceptions). Many of the worst results were among our closest allies, where confidence in the American president dropped by 60, 70, or even 80 points.

Or as Trump might describe it, "so much winning you'll get tired of winning."

Yet there is no reason to think that even if things get worse, he'd be capable of assessing his mistakes and adjusting course. It's his nature to insist that everything is going great, and he has enough people telling him the same thing that he can believe it's true. If you've watched Fox News lately — particularly the shows Trump favors, like Fox & Friends — you've learned just how amazing a president he is. So extraordinary in his wisdom, so superior in his strategic cunning, so pure in his love of America, so remarkable in his accomplishments, only the most sinister and dishonest of the haters and losers could possibly question him.

Which helps explain why Trump is so consumed with rage when he sees other media outlets criticize him or report on his failures. If they're alleging that this isn't the most successful presidency in living memory, it can only be because of their cruel and unjustified bias. Whenever Trump blames the mainstream media for his troubles, he receives immediate reinforcement from the conservative media, which after all built its entire ideology on the idea that supposedly "objective" news outlets are in fact rancid cauldrons of liberal bias. They help Trump deflect blame, and perhaps more importantly, reassure him that he's right to do so.

No matter what happens, Trump's belief in himself will not change. He knows deep in his heart not just that he can succeed, but that he is succeeding. Or at the very least, that if he tells us all that it's true, then it just might become true.