More than any political candidate in memory, Donald Trump's value proposition to voters is simple and crystal clear: He's a winner.

Everything else follows from that. He doesn't owe wealthy political donors or political elites anything. He'll get the best trade deals and kick the most terrorist ass. He'll defy political correctness and tell it like it is. ISIS will give us its oil. Mexico will pay for our wall. Corporations will beg us to relocate their factories to the US.

Why? Because Trump is a winner. "We will have so much winning if I get elected," he assures us, "that you may get bored with winning."

This message has proven astonishingly resilient, to the point that the entire US political class is flummoxed. Attacks just bounce off the guy. What could ever bring him down?

No one seems to know. The other day, Vox's Ezra Klein mused about what a Trump loss might look like. He said it will just ... happen. Trump will be winning, and then he won't be. No one will predict it beforehand; hundreds of hot takes will explain it in retrospect.

I think Klein is right that Trump will fall; I am among those who believe such a fall is inevitable. There's some slim chance Trump could become the GOP nominee, but if he does, I'm not the only one thinking the odds of him beating Clinton in 2016 are vanishingly small. (Maybe someday I'll eat those words.)

Anyway, whether or not we can predict the timing of Trump's fall, I think it's possible to say something about how and why it will happen. And it won't be, contra Klein, Trump supporters becoming "more pragmatic."

Rather, the seeds of Trump's destruction can be found in his greatest strength. To put it bluntly: If your value proposition is that you're a winner, your value evaporates the minute you're no longer winning. Losing refutes a winner, and no one wins forever.

People like winners who win

A hint about how Trump might finally go down can be found in some replies to Klein's piece by political science PhD candidate Kevin Collins:

There's good reason to think he will fall short of expectations in Iowa. His supporters are lower propensity voters, and — Kevin Collins (@kwcollins) January 5, 2016

... he's already falling behind Cruz: https://t.co/Hjh4UXXj2L — Kevin Collins (@kwcollins) January 5, 2016

But so much of Trump's appeal is about being a winner. So what happens when someone who's built his campaign on that basis falls short? — Kevin Collins (@kwcollins) January 5, 2016

Fortunately, there's academic research to tell us. Before The Party Decides, there was actual research on how voters choose in primaries — Kevin Collins (@kwcollins) January 5, 2016

Research by Bartels (observational) expectations of a candidate's chances and support are highly correlated, esp among low info voters. — Kevin Collins (@kwcollins) January 5, 2016

The research he's referring to, conducted by political scientist Larry Bartels (now at Vanderbilt University) and published in 1985, found that in close, ambiguous political contests, preferences and expectations are tightly related and mutually reinforcing. There's a "bandwagon effect" that sees voters, especially low-information voters, flock to the candidate most expected to win.

I don't know how much we should rely on 30-year-old research about voter preferences, given the ways American politics has changed even in the past few years. But I do think Collins gets at something essential.

Trump's vulnerability (like his strength!) is that his appeal is entirely personal, entirely based on the expectation that he's a winner who will win. He's an alpha male, the top dog, the guy with the balls and the leverage to get the good deals, the guy who can't be intimidated, the self-made, independent guy who's not afraid to say what everybody's thinking. "I play to people's fantasies," he wrote in The Art of the Deal. "People may not always think big themselves, but they can still get very excited by those who do. That's why a little hyperbole never hurts."

That hyperbole has been fervently embraced by his supporters, independent of any policy positions. Policy positions are simply not the point. Indeed, when the Trump campaign puts his platform into the traditional framework of a campaign commercial, it almost comes off like a parody:

"Stop Muslims coming into the US ... until we can figure out what's going on." If this is a policy position, your right-wing uncle's Facebook rants are a think tank.

The point isn't what Trump will do, it's who he is: someone who will stand up the Mexicans and Muslims and politically correct liberals and turncoat Republican pols and biased journalists. His rhetoric is full of dominance displays. That's what all the insults are about. They work because he's winning.

Beneath every narcissist is a scared kid

But those who live by personal appeal die by personal appeal.

You don't have to be a psychologist to understand what's really going on with Trump. His entire career, like his campaign, has been about declaring his awesomeness and forcing others to acknowledge it. He has surrounded himself with trophy wives, sycophants, and his own name, everywhere he looks. He built a whole TV show premised on the idea that he's a savvy, decisive business executive, harvesting obeisance from the rotating cast of supplicants. It is overcompensation on a world-historical scale.

At the root of this kind of narcissism is always the same thing: a vast, yawning chasm of need, a hunger for approval and validation that is never sated. Down there in the lizard brain, it's fear: fear of being left out, laughed at, or looked down on, fear of never belonging, never being accepted, no matter how many towers you build.

The fear can only be calmed by validation, by accumulating visible markers of success until no one can laugh at you. There's a submerged glacier of insecurity beneath every blowhard. (I fear that conservative primary voters, as a class, are insufficiently aware of this important fact.)

Trump has built a life around being constantly validated, and his primary run so far has only seen him in that mode: winning, punching down at weaker opponents, being showered with adoration.

But the thing about politics is it's not an episode of The Apprentice. Despite the evidence of the past few months, it is not designed to make Donald Trump feel important and powerful. Sooner or later, everyone in politics is humbled. Everyone loses, at least a news cycle or two. Every politician has to eat shit, more than once, and smile through it. Eventually they must decide that eating all the shit is worth it for the chance to do some good.

That's what Obama was getting at in this interview — if people running for president don't have a powerful desire to make the country better, it's not going to be worth it. "If you are interested just because you like the title or you like the trappings or you like the power or the fame or the celebrity," he said, "that side of it wears off pretty quick."

Trump, however, is not willing to eat shit for the greater good. His enormous ego is, like the ego of every blowhard, incredibly tender. He legendarily never forgets a slight. Twenty-five years ago, Vanity Fair editor Grayson Carter called Trump a "short-fingered vulgarian," and to this day it rankles Trump. He sends Carter pictures of his fingers, insisting they are normal size. Really!

Even today, Trump's rallies have become long, discursive rambles in which he addresses and rebuts every single accusation cast at him by his detractors. (Responding to criticisms of his rhetoric: "I went to an Ivy League school. I’m very highly educated. I know words, I have the best words.") He can't let go of any slight. His whole life has been devoted to refuting those who doubt the awesomeness of Trump.

Trump supporters may find Trump less charming as a loser

The kind of persona-based, expectations-based support Trump is receiving works as long as it's working. It wins as long as it's winning.

But "I always win" is a brittle claim. All it takes to disprove it is a single loss.

And eventually, Trump will lose something — maybe Iowa, maybe New Hampshire, maybe just a couple of news cycles. (And make no mistake: To a winner, second place is losing.) When he's being pressed to explain his loss, what he did wrong, do you suppose he will acknowledge error?

No. What error could there be? He can't communicate his message any better. The message is Trump. And he's Trump! If voters aren't voting for him, they're stupid.

The reactionaries who are attracted to Trump are, as numerous lines of research have demonstrated, more anxious than liberals and thus more prone to value order, stability, structure, and social hierarchy. They are highly sensitive to the pecking order and in-group/out-group distinctions.

This has served Trump's nationalist, xenophobic campaign well, but it could come back to bite him if he becomes second man on the totem pole — or, god forbid, third. To the hierarchy-conscious, the way things work is you pay respect to the winners above you. You only punch down at the losers below.

Under attack, or in the face of skepticism or, y'know, losing, Trump's thin skin will make him defensive and volatile. He can't modulate, can't do humility, can't abide the thought of anyone above him. All his claims, all his stories, all his insults are yuge, the best you'll find anywhere.

The same belligerence that looked like strength when Trump was on top will look defensive and bitter when he's not. And the more doubtful or skeptical voters and the media become, the more Trump will escalate, the more his chest will puff. He doesn't know any other strategy. He'll enter a negative spiral as self-reinforcing as his rise has been.

For as long as he's been in the US public eye, Trump's been winning. He won every week on The Apprentice, and ever since he descended on his classy escalator, he has dominated every week of the GOP primary. Most of his supporters (few of whom reside in New York City) have never seen Trump when he's losing.

I suspect they won't like it. And he won't like them for not liking it. And they won't like that either. And so will go the inevitable fall.