Eight weeks before the US election, President Donald Trump is hurtling down a rabbit hole of conspiracy theories filled with black-clad saboteurs, "dark shadows," the deep state, QAnon, and claims that he is victim of a coup and/or plans to rig the polls.

The Republican's latest story is that a planeload of agitators deployed to disrupt his party convention in Washington last week -- or something like that.

"We had somebody get on a plane from a certain city this weekend and in the plane it was almost completely loaded with thugs wearing these dark uniforms, black uniforms, with gear and this and that," he told Fox News on Monday.

On Tuesday, he told reporters about an "entire plane filled up with the looters, the anarchists, the rioters."

The president then teased: "I'll see if I can get that information for you."

He didn't.

US President Donald Trump is fanning Americans' penchant for conspiracy theories
US President Donald Trump is fanning Americans' penchant for conspiracy theories AFP / MANDEL NGAN

But distinct similarities emerged between Trump's plot and a conspiracy theory about airborne leftist provocateurs circulating on Facebook earlier this summer, prompting US media to ask if that was his supposedly secret source.

Fact checking has become an industry in the age of Trump. Keeping up, though, is impossible.

In the same Fox interview, Trump said that Biden, who leads in many polls ahead of the November 3 vote, is a puppet controlled by "people that you've never heard of, people that are in the dark shadows."

"Sounds like a conspiracy theory," the Fox interviewer, Laura Ingraham, said.

"They're people you haven't heard of," Trump repeated.

This man wearing a QAnon shirt joined a rally held by President Donald Trump in New Hampshire
This man wearing a QAnon shirt joined a rally held by President Donald Trump in New Hampshire AFP / Joseph Prezioso

The men in black and "shadows" narratives are just two threads in a Trump tapestry depicting his presidency as besieged by an unidentifiable "deep state" seeking to wreck his first term and fixing the election to ensure he doesn't get a second.

He characterizes official probes into his relations with Russia -- which US law enforcement has repeatedly accused of working to boost Trump's 2016 election chances -- as a "hoax" and a "coup." Almost daily, he claims that increased mail-in voting, due to the coronavirus pandemic, is a gambit to "rig" the November election against him.

The scale of the claims, made without evidence, is not far off the viral QAnon conspiracy theory that has been bubbling under the surface ever since early in the Trump presidency.

QAnon posits that an anonymous, high-level government insider codenamed Q is heroically working to expose an anti-Trump cabal which is somehow also running an international Satanic pedophile child-trafficking ring and controlling the world.

Q has ever-growing numbers of supporters both online and in real life, including among members of the public who come out to cheer Trump at rallies or other events. A Republican QAnon believer, Marjorie Taylor Greene, just won selection to run for a congressional safe seat in Georgia.

Trump, who heartily congratulated Greene, is doing nothing to tamp down Q fever.

"It is gaining in popularity," Trump said approvingly last month. "They like me very much."

Rich Hanley, a professor at Quinnipiac University's School of Communications, says Trump reflects -- and profits from -- a society ever more lost in the smoke and mirrors of the internet.

"He may be an outlier among presidents, but not among a growing number of conspiracy theory loving Americans," Hanley said.

And with presidential election results potentially coming out only days after the polls close, due to much greater use of mail-in voting, paranoia and rumor-mongering is likely poised to hit an all-time high.

"It will be the Woodstock of conspiracy theories regardless of who wins, because this sort of fiction is so embedded now in the alternate reality of millions of people," Hanley said.