Secretary of Defense James Mattis’s decision to resign, complete with a strongly worded letter slamming President Donald Trump, is not so much the end of “adults in the room” safeguarding the country from the president’s worst instincts as it is the end of the myth that there ever were any such adults.

Mattis was, after all, recommended to Trump in the first place because Barack Obama had fired him for his reckless advocacy of military confrontation with Iran. And while the last grown-up was unable to restrain Trump from imprisoning asylum-seeking children, abusing his pardon power for Joe Arpaio, abusing declassification power, undertaking a partisan purge of the FBI, cheering the French far right, or issuing apologias for neo-Nazis, he finally decided to take his stand over Trump making the perfectly defensible decision to withdraw US forces from a hazily defined open-ended mission in Syria that lacked any legal authorization.

There’s nothing wrong with quitting over a policy dispute that you feel strongly about. (Though, frankly, I think Trump is on the right side of this one.) But that's all this was — a normal dispute within the range of things reasonable people can disagree about.

At the end of the day, Mattis proved ineffective or uninterested in preventing shocking abuses of power and flagrant immorality only to throw down over a perfectly legitimate order from the commander in chief.

And while resigning sooner, over something better, would have been welcome, the notion that it could have meaningfully improved outcomes is silly. Trump is unfit for office, and flagrantly so, in ways that are fairly obvious and have been obvious for years. There are no adults in any room he leads, and there never will be. The real grown-ups are the ones who’ve been outside the room trying to get him out of office.

The “grown-ups” never accomplished much

As of this week, the wheels seem to be coming off the Trump bus. But that’s only a reminder of the many times before when the wheels seemed to be coming off the bus.

It was way back in the spring of 2017, back in the Peak Grown-up Era, when Trump broke the unwritten norms of the American government to fire FBI Director James Comey for improper reasons and then lie to the public about why he did it. Trump followed that with a bizarre Oval Office meeting with the foreign minister of Russia, at which he called Comey a “nut job” and said firing him took pressure off his administration. He also passed highly classified Israeli intelligence on to the Russians for no known reason.

The grown-ups didn’t stop any of that. Indeed, former grown-up H.R. McMaster was put out to defend it. McMaster and fellow grown-up Gary Cohn also penned an op-ed reassuring the world that “America First Does Not Mean America Alone,” only to watch the president repeatedly trash NATO and officially declare that imported Canadian aluminum was a threat to American national security.

Cohn, a former top-ranking executive at Goldman Sachs and extremely rich person, for his trouble got to help put through a regressive tax cut and, eventually resurface lecturing freshman members of Congress on the ways of the world. McMaster used his sway to convince Trump to stick around a bit longer in Afghanistan, ultimately futilely since now Trump is ready to leave anyway.

Perhaps most tellingly of all, “grown-ups” seem totally incapable of influencing Trump’s behavior with regard to North Korea, where the president has veered wildly between irresponsible threats, bizarre credulity about the country’s dictator, and boasts about totally nonexistent diplomatic breakthroughs.

It’s not the grown-ups’ fault, exactly, that they can’t control Trump. But that just shows the basic faultiness of the metaphor. When toddlers play, it’s good to have a grown-up in the room to supervise. But if a toddler is driving a car, it does no good to have a grown-up in the passenger seat. Pretending that it’s somehow okay is the least grown-up reaction possible.

Congressional Republicans are being worse than useless

Having someone terrible win a presidential election even though he was never popular and got way fewer votes than his opponent is an inherently crappy situation.

But what’s brought America through these two agonizing years has not been the absence of “adults in the room” but the failure of congressional Republicans to do their job. Though it would have been easy to do so, they’ve never demanded financial transparency from Trump and never conducted an ounce of meaningful oversight of the obviously inappropriate use of his unqualified son-in-law as a diplomatic emissary.

Despite stated objections to his tariff policy, congressional Republicans don’t pass laws that would constrain the national security loopholes he’s exploiting.

And far from pushing back on his anti-immigrant demagoguery, they actively cheerlead for stunts like his dispatch of troops to the border — and now they’re attempting to give him political cover for this ridiculous pre-Christmas government shutdown.

Most of all, congressional Republicans have taken to actively abetting Trump’s various efforts to obstruct special counsel Robert Mueller’s inquiry and politicize the FBI and the Department of Justice.

Which is just to say that, in the aggregate, Trump is far from a maniac whom the Republican establishment is restraining. In reality, he is mostly inept but constantly having many of his most destructive ideas cheered by establishment leaders who see electoral upside in doing so. All of the actual adults are on the other side, trying to get rid of him.

The real adults are in the resistance

Trump is not inexperienced, naive, or in need of expert guidance.

He’s simply unfit for the presidency in ways that have always been clear. He lacks relevant subject matter knowledge, disposition to learn, empathy, respect for the rule of law, or comprehension of American values.

And in response, millions of people have, over a period of years, attended marches and rallies, contributed to and volunteered for campaigns, and otherwise added to the anti-Trump resistance. Those people are, so to speak, the adults in the room: the ones trying to get an unfit president and his enablers out of office so that they can be replaced by other, more competent people.

I don’t think that Mattis will join them after he retires, but I hope he does. And it’s unquestionably true that his sternly worded resignation letter was a good start. More likely, though, he’ll end up slinking off to wherever McMaster and Rex Tillerson hang out to quietly burnish his own reputation.

That would be too bad. Because of the basic dynamics of partisan politics, the resistance is dominated by progressive types who are instinctively alienating to people with conservative worldviews. Hearing the truth about Trump from people like Mattis could play a very constructive political role. But as window dressing, Mattis and all the other grown-ups were playing a destructive role.

America doesn’t need illusions

Between stints in government, Mattis found himself on the board of directors of Theranos, a blood testing company that’s now known to be a giant fraud.

Over the years, Mattis played a small active role in perpetuating the fraud by pushing for the military to use Theranos’s technology. This would, in retrospect, have been a big mistake, since the technology was fake.

Mainly, though, he was a bit player in the company’s actual work who wasn’t personally involved in the fraud. His role as a director was simply to cash checks and lend the company an air of respectability. After all, the whole thing couldn’t just be a ridiculous scam if there were grown-ups in the room like Mattis on the board of directors. Except it could.

His role in the Trump administration was fundamentally similar. Say you’re a CEO who feels conflicted about the Trump administration. On the one hand, the fact that he’s in office helps make you richer pre-tax through lax regulation and post-tax by lavishing rich people like you with tax cuts. On the other hand, you might worry that having a wildly unfit president in office poses some downside risks. Well, you think, it’s all good because Mattis is around.

That’s a convenient rationalization, and it is upon dozens of such rationalizations that Trump’s continued hold on power is built. The reality is that, Mattis or no Mattis, Trump is the president, and Trump says and does wildly inappropriate things all the time. It’s a scary situation, and people ought to know exactly how scary it is.