President Donald Trump’s firing of Secretary of State Rex Tillerson via tweet is, as a metaphor for the overall Trump administration, almost too on the nose.

Tillerson was supposed to be one of the “adults in the room” — a sober, seasoned steward who would protect the country from Trump’s worst instincts. Tillerson, Secretary of Defense Jim Mattis, National Security Adviser H.R. McMaster, Chief of Staff John Kelly, White House Economic Council Director Gary Cohn — these were the bulwarks between America and Trump’s tweets becoming law.

But now Tillerson is gone. So is Cohn, who resigned exactly a week before Tillerson was fired. The latest reports from inside the White House suggest that Kelly and McMaster are next on the chopping block. Mattis is the only so-called adult whose spot in the administration seems secure.

What’s worse, they seem to have failed in their mission to corral the president.

Trump decided to move the US Embassy in Israel to Jerusalem — a move that experts say has already made it harder for the US to broker an Israeli-Palestinian peace deal. He withdrew from the Paris climate agreement, decertified Iranian compliance with the nuclear deal, said there were “good people” among the white supremacists marching in Charlottesville, Virginia, and imposed dangerous tariffs on steel and aluminum imports because he was angry about bad press coverage.

All of this points to one obvious conclusion: The idea of the “adults in the room” was a comforting myth. The truth is that no number of advisers, no matter how skilled, can control a president as erratic as Trump.

Rex Tillerson’s ouster highlights why the “adults” couldn’t stop Trump

The fundamental problem with the “adults” theory is that it assumed a group of subordinates could successfully trick their boss for years.

Tillerson did try to manage Trump. He reportedly argued for staying in the Paris agreement and for certifying Iranian compliance with the nuclear deal. When Trump was publicly threatening to go to war with North Korea last year, Tillerson tried to reach out to Pyongyang and start negotiations.

But he never managed to persuade Trump to see things his way. And when he lost an argument, he’d end it by saying, “It’s your deal,” per the New York Times — a habit that reportedly annoyed the president.

Trump would even publicly shame Tillerson. After Tillerson’s offer to open negotiations with North Korea last year, Trump sent a tweet telling him to stop “wasting his time”:

I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man... — Donald J. Trump (@realDonaldTrump) October 1, 2017

...Save your energy Rex, we'll do what has to be done! — Donald J. Trump (@realDonaldTrump) October 1, 2017

Maybe Tillerson is just not a particularly persuasive guy. And it’s an open secret in Washington that Trump and Tillerson didn’t like each other very much on a personal level.

But the deeper problem, confirmed by virtually every well-sourced White House reporter, is that Trump truly hates being managed. When people tell him what to do, he’s inclined to do the opposite.

“Aides say the quickest way to get Trump to do something is to tell him he can’t,” Axios’s Mike Allen writes.

The whole theory of the “adults in the room” was that they could somehow manage this man who hates to be managed. That they could steer him away from destructive policy ideas he repeatedly endorsed on the campaign trail, like starting a trade war or tearing up international agreements, through clever stratagems or sheer force of will.

But this could only go on for so long before Trump realized he was being played — that his advisers didn’t agree with him on policy and were simply trying to stop him from doing what he wanted. Once Trump figured that out there was nothing the so-called adults could do to stop the president. He’s their boss, and he could overrule them easily if he wanted.

Eventually, the buck stops with Trump. Either the aides acquiesced and tried to make the best of a bad policy or they left the White House — quitting like Cohn, or getting fired like Tillerson.

The ultimate problem has always been Trump himself

The counterargument here is that the adults may have been doing things to constrain Trump behind the scenes but they just haven’t made it out to the press. Letting the public know that they had successfully reined in Trump would be a disaster, as the president pays close attention to what the press is saying about him. So they may have successfully gotten Trump to back off from some idea but made sure no reporters found out about it lest Trump feel embarrassed and change his mind again.

This could be true. It’s quite possible that Rex Tillerson is leaving behind a legacy of, say, stopping Trump from attacking North Korea, and we won’t find out about it for years, if not decades.

But there’s no reason to believe in such an elaborate theory absent evidence for it, and so far, there’s precious little to suggest that Tillerson and the others were any more successful privately than they were publicly.

The simpler explanation for what’s happening is the obvious one. On the issues Trump didn’t have deep or long-held opinions on — like how to respond to Syria’s use of chemical weapons — the “adults” could plausibly shape US foreign policy in a more conventional direction. But on issues that were nearer and dearer to the president’s heart, like tariffs and certifying the Iran deal, the advisers were fighting a losing battle against Trump’s instincts.

This speaks to the most important dynamic of the Trump presidency: It’s the Trump presidency. And no amount of seasoned or thoughtful advice, no matter how well-intentioned, can change the fact that he’s the man at the head of the US government.

For more on Rex Tillerson’s devastating tenure and what it means that he’s gone, listen to a special episode of Worldly: