Mitt Romney said during his 2012 presidential campaign he’d like a provision in the Constitution to “say that the president has to spend at least three years working in business before he could become president of the United States.”

Trump’s son-in-law and senior adviser Jared Kushner parroted this theme in an interview this March: “We should have excellence in government … The government should be run like a great American company. Our hope is that we can achieve successes and efficiencies for our customers, who are the citizens.”

And yet, there is no evidence that businesspeople make good politicians. Historians certainly haven’t found any.

Nevertheless, a big part of Donald Trump’s appeal as a presidential candidate was that he was going to bring his “on time and under budget” philosophy to Washington. He was going to run the country like a business.

So far it hasn’t worked. At nearly every turn, Trump has undermined his own agenda. And his administration is failing precisely because Trump is running the country like he ran his business.

His most recent misstep, firing FBI Director James Comey a few months after reportedly asking him to drop the investigation into his former National Security Adviser Michael Flynn, is a perfect example.

CEOs don’t persuade people; they dictate. And they fire those who refuse to carry out their demands. Even more importantly, a CEO of a privately held company (like the Trump organization) operates like a king over his personal fiefdom. His employees work for him; they have no higher obligation to shareholders.

This is how Trump has governed — demanding do-or-die votes in Congress, threatening legislators who don’t toe the line, and bullying a FBI director into abandoning an inconvenient investigation.

You can behave like this when you’re the chief executive of a company with your name on it. But it doesn’t work and is wildly inappropriate when you’re the president of the United States.

To better understand why Trump’s business ethos is failing him, I reached out to Gautam Mukunda, a political scientist and professor at the Harvard Business School. I asked Mukunda why Trump’s unique business background has ill-equipped him for this job, and why his self-destructive behavior makes sense when you consider how Trump has operated in the private sector his entire career.

Here’s what he told me.

Trump has spent most of his business career surrounded by sycophants, by people who work for him and not an actual company. As a result, he expects fidelity to him and not to the law.

The Trump organization is a privately held company; it's not a publicly held company. His adventures (and adventures is the right word for it) with publicly held companies were debacles, just complete disasters for everyone except Donald Trump. Publicly held companies at least have constraints and restrictions — there are shareholders who can vote you out, there's a board of directors, there are various legal obligations.

But privately held companies are fiefdoms. They're essentially extensions of the owner, of the individual behind them. Recall that the Trump organization is a LLC, a private limited company, and so it's pass-through entity, which means it has no real existence — it's a fiction. The IRS treats it like it doesn't exist. Legally, the Trump organization is just an extension of Trump and his brand. There is no distinction between him and his company.

And so this is a guy who has spent almost his entire career in this environment in which nearly every single person who works for him literally works for him and not for the company. When a CEO says my employees work for me, what they mean is that they work for the company, and they actually have higher obligations to the company than to the CEO. That's not true for the Trump organization. No one has any obligations except to Donald Trump.

When you look at Trump's behavior, it's clear that he thinks of the government in the same way. He doesn't get that there are separations, that people have responsibilities to things other than Trump.

Trump is used to functioning as a tyrant within his own world, and that’s how he is governing.

The CEO of a public company has powers that vastly exceed those of a president, but the CEO of a sole-owned private company has powers that vastly exceed those of a CEO of a publicly held company. So that's the backdrop against which Trump is acting, and it really does clarify some of his tyrannical behavior.

Trump fired Comey as though he were an employee of Trump’s organization, not the independent director of the FBI.

I think he fired Comey because he thinks Comey was engaging in what he views as insubordinate behavior. He appears to have thought, "How dare this man use the resources of my own organization to investigate me." And that is how you can make sense of his unbelievably self-destructive behavior. Because if you were an employee of the Trump Organization and you did this, he would fire you and there would be no problem with doing that. Of course, that’s not how it works in government, where there are rules and norms and laws and institutions.

Trump’s business experience has perfectly ill-equipped him for political office.

Trump's background in business could not have prepared him less for the job he has now. The only times he has dipped into an environment in which he had to serve masters other than himself, it was a total disaster. Even when he built casinos, the only person he was ever able to serve was himself. He made a profit, he paid himself enormous consulting fees, even as his shareholders were taken to the cleaners. It’s not hard to see how this approach would be a disaster when applied to the presidency.

If you want to understand Trump’s myopic and impulsive behavior, look at how he has conducted business his entire career.

Here's the unifying theme that ties together a lot of Trump's reckless behavior: If you conceive of every relationship as a one-time exchange. If every time you interact with someone, you're thinking this is the only time I'm ever going to interact with this person, you're free to "win" the exchange without worrying about long-term costs because there won't be any long-term costs.

And this is all Trump has ever done. And it works if you're a Manhattan real estate developer, because there's always going to be another sucker looking to move to Manhattan. But navigating the machinery of a liberal democracy is not at all like this. You can't treat political actors in this way and expect to get anything done.

You can make a lot of money in the business world that Trump inhabits by treating every interaction as a one-time exchange. The downside, of course, is that no one will ever make a deal with you more than once. There are businesses where you want to create long-lasting relationships with clients, but that's not the kind of business that Trump has done. Nearly everything for him has been a one-shot deal, and that's it.

No one buys a second car from a shady used car dealer, and hardly anyone wants to make a second deal with Donald Trump.