This week’s reminder that the President of the United States is a moron came, as it so often does, in tweet form.

Last weekend, Donald Trump all but accused Joe Scarborough, a former Republican congressman, MSNBC host and a friend-turned-foe of the President, of murder. Repeating a debunked conspiracy theory, Trump insinuated that Scarborough was responsible for the death of Lori Klausutis, who was working in Scarborough’s congressional office when she died in 2001. Ignoring the pleas of Klausutis’s widower, and the condemnation from usually loyal media allies, Trump pursued the line of inquiry on and off for several days. Throughout the unseemly spectacle, the President’s most shameless boosters have mustered little more than looking the other way.

Does Trump think one of his media gadflies killed a staffer? Probably not. But then he probably doesn’t think Republican Senator Ted Cruz’s father was the Zodiac killer, or that Barack Obama was born somewhere other than the United States, or that conservative Supreme Court Justice Antonin Scalia was murdered.

So why has he pushed all these wacky conspiracy theories?

To some on the American left, this is evidence of Trump’s sinister brilliance: the master manipulator activating the darkest corners of the internet and preparing his army of trolls to do battle ahead of November’s election. Vox, for example, described the President’s actions as “weaponising” a conspiracy theory, calling it a move from the “Trump playbook”.

Scarborough himself, no shrinking violet, characterised Trump’s tweets as an authoritarian tactic in an interview with The New York Times. “It’s remarkable that we have a president who is trying to have someone prosecute the person he considers to be his chief critic in the media,” he said, with characteristic humility. “That’s what Putin does. That’s what Orban does. That’s what autocrats have been doing for centuries.”

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Accusations of authoritarianism are a daily occurrence in Trump’s Washington. When I hear them, I am often reminded of a scene in The Big Lebowski. The Dude (Jeff Bridges) has just been visited by black-booted Germans threatening to “cut off your johnson”.

Talking the incident over at the bowling alley, his short-tempered Vietnam veteran friend Walter Sobchak (John Goodman) is convinced that the intruders were Nazis: “Come on, Donnie, they were threatening castration. Are we going to split hairs here?”

The Dude corrects him. “They were nihilists, man. They kept saying they believed in nothing.”

Walter is unsettled: “Nihilists? Fuck me. Say what you will about the tenets of National Socialism, dude. At least it’s an ethos.”

A nihilist, not a Nazi. That Lebowski-derived refrain may be the best response to much of the histrionics that Trump incites. The President has opinions. Some are even quite strongly held, for example, on trade, immigration and China. (Trump and China is the subject of my piece for this month’s print edition of the magazine.) But none of these of these convictions take precedent over the nihilism at the heart of the Trump project.

To Trump, everything is relative and nothing beyond his own ego really matters. It’s this nihilism that makes crazy conspiracy theories “interesting” even when there’s zilch to suggest they might be true. It’s this nihilism that means new White House Press Secretary Kayleigh McEnany’s daily display of insincerity and whatabouttery so delights her boss.

Why won’t the President wear a mask in public? Why won’t Joe Biden wear a mask in his own home to protect his own wife?

Why did the President tweet conspiracy theories about the death of a Scarborough staffer? Why did Scarborough laugh at a joke referring to the tragedy in a 2003 interview?

Russiagate? Obamagate!

It’s unedifying and unbecoming. It’s the behaviour of a rattled administration conscious that it is a long way from where it would like to be in the race for re-election. But is it really evidence of creeping authoritarianism?

Like Walter Sobchak, Trump’s opponents seem to prefer the idea that the President is something worse than a nihilist. It means their target is more clear cut, and it makes their stand all the more heroic. But they have brought a knife to a clown show. And, in overestimating the forces they are up against, they have indulged in too much conspiratorial thinking themselves. The sooner the anti-Trump coalition stops taking all of this so seriously, the better chance they have of triumph in November.

When, in The Big Lebowski, Walter sees the nihilists for what they are, he realises they are cowards and *spoiler alert* beats the living daylights out of them in the bowling alley carpark. For Trump’s opponents, victory starts with a similar revelation.