Donald Trump, conspiratorialist in chief

President Trump. h)Susan Walsh/AP/Associated Press

During the course of our long history, certain of our presidents have had odd, unsupported, or downright conspiratorialist views.

Andrew Jackson wrongly thought a secret deal between John Adams and Henry Clay had cost him the 1824 presidential election. Benjamin Harrison was so scared of electricity, introduced to the White House during his presidency, that he wouldn’t turn the lights on or off.

FDR was a triskaidekaphobe — that is, one skittish about the number 13. Richard Nixon saw cabals everywhere aligned against him. Ronald Reagan let the advice of his wife’s astrologer help guide his political schedule.

But Donald Trump — well, as he himself has noted in another context, there has never been a president like President Trump. He has made the White House conspiracy-theory central. His latest descent into kookiness came over the weekend, when he retweeted a suggestion that Bill Clinton was somehow behind the death of accused sex trafficker Jeffery Epstein, who died in prison on Saturday of what federal officials call “an apparent suicide.”

But Trump doesn’t just traffic in conspiracy theories. He weaponizes those unhinged assertions — and by so doing, encourages his diehard supporters to follow him deep into the rabbit hole of irrationality. Take his oft-repeated assertions that federal investigators have long been engaged in a conspiracy against him. If supposed “Deep State” actors had been determined to do in Trump, why didn’t they, before the 2016 election, leak word to several high profile media outlets that the FBI was probing possible collusion between the Trump campaign and Russia?

That would likely have led to his defeat. Instead, the candidate who suffered publicly from autumn FBI intervention was Hillary Clinton. That came in the form of a reopening of the probe into her e-mails in the final days of the 2016 presidential campaign.

Yet for all its myriad illogic, Trump’s Deep State charges are an article of faith for many of his supporters. Logic, of course, doesn’t dissuade conspiratorialists, who are always attributing unwelcome or surprising developments to shadowy forces of seemingly limitless power.

Mind you, that inclination isn’t just a conservative mental failing; the 9/11 Truth movement, with its wild-eyed theories about the World Trade Center attack, was a prime left-wing example. Bernie Sanders, meanwhile, just indulged in a little conspiracy-theory mongering of his own, suggesting his tough talk about Amazon has led to critical coverage by The Washington Post. (Both are owned by Jeff Bezos.)

Still, the susceptibility of both sides to conspiracy theories shouldn’t imply symmetry. As historian Richard Hofstadter noted decades ago, conspiratorialist paranoia has long characterized a strain of conservative thought. And these days, that kind of nuttiness is primarily the product of right-wing fever swamps.

In part, that’s due to the truth-toxic nature of today’s Republican Party, which features a national (mis)leader who uses codswallop to reinforce his lightly informed, easily gulled, and worshipful base — and an assembly of elected Republicans nervous of running afoul of either.

It’s what leads to mental malaria like the Obama birth-certificate idiocy or the current Deep State-ism. Or the repeated, ridiculous assertion that several million undocumented immigrants voted for Hillary Clinton.

Whether Trump actually believes any of the fact-free fatuity he traffics in is difficult to say, but much of it is obviously cynical. How else to explain the evolution of his argument about Clinton’s e-mails in the closing days of the 2016 campaign? In a week and a half, he went from contending that a biased FBI had wrongly cleared Clinton in a rigged probe to saying that, by reopening that probe, the bureau had apparently decided to do the right thing, to asserting that the FBI hadn’t really reviewed all the newly discovered e-mails and had instead cleared Clinton despite knowing she was guilty.

But whatever the ratio of cynicism to stupidity, the public effect is the same.

The president is aiding and abetting this nation’s lamentable penchant for paranoid nonsense — and doing so at a time when the country sorely needs clear reasoning and common purpose.