“Conspiracy theory” — the label evokes connotations of something so preposterous that it couldn’t possibly be true.

With an obvious simple explanation for some incident easily at hand, generally involving a single perpetrator or a natural cause, the alternative “conspiracy theory” posits that a large group of people plotted to bring the incident about. The very size of the posited group alone makes the conspiracy theory seem unlikely, because such a large group could never hope to keep the secret.

And then, in the classic conspiracy theory, the large group of conspirators consists mostly or entirely of agents of the government, who have allegedly acted in nefarious and illegal ways against the interests of the people they are sworn to serve, and have then also covered up their illegal conduct. Our government employees and officials may not be perfect, but surely they would not carry out, and then cover up, massive illegal conspiracies against the interests of the people.

Put these factors together, and you can see why sticking the label “conspiracy theory” on a hypothesis has long been an effective way to dismiss that hypothesis out of hand.

A few days ago, pursuant to an order from President Trump, the National Archives finally released some 76,000 pages of documents that were previously withheld as classified from what they call their President John F. Kennedy Assassination Records Collection.

Many voices — not the least of them Robert F. Kennedy, Jr., the current Secretary of Health and Human Services and nephew of the slain President — have been calling for the release of these documents for years, even decades. Surely today, more than 60 years after the event, the secrets that justified withholding these documents from the public for decades can’t be all that significant any more. So let the truth be known!

A big reason given by those advocating for the release of the documents has been that it might put an end to the so-called “conspiracy theories” that have long swirled around the assassination of President Kennedy.

Since immediately after the assassination, the official government story has been that Kennedy was killed by a single lone gunman, Lee Harvey Oswald, who acted entirely on his own. That version of the facts got the ultimate official stamp of government approval with the issuance of the Warren Commission Report on September 24, 1964, about 10 months after the assassination. President Lyndon Johnson had appointed the blue ribbon Warren Commission specifically (supposedly) to get to the bottom of what had happened. The Commission was headed by Earl Warren, then the sitting Chief Justice of the Supreme Court, and included as members such luminaries as future President Gerald Ford and then-recently-retired head of the CIA Allen Dulles. The Commission’s Report is long, detailed, and seemingly definitive. Since the issuance of the Report in 1964, the government’s official story has never changed.

And yet, when polls are taken of the American people even today, the large majority don’t believe it.