America’s penchant for conspiracy theories can be traced back to the nation’s founding. And as recent events confirm, our thirst for embracing ideas that unseen forces and assorted nefarious boogeymen are pulling the political strings and killing those who might change the status quo like the Kennedys or those who know too much like Jeffrey Epstein remain unquenched.

Hollywood, like America, took a few years to process the too-deadly-to-seem random political assassinations of the 1960s.

Sinister, unseen “secret programs” and megalomaniacal tycoons or bureaucrats turned up in thriller after thriller in one of the cinema’s greatest decades, the ’70s. From “The Conversation” to “Winter Kills,” with “The Anderson Tapes,” “Marathon Man,” “Three Days of the Condor” and “The Odessa File” just a few of the more famous examples, the movies set out to make us paranoid in “The Me Decade.”

When the best conspiracy picture of them all, “All the President’s Men,” arrived and put an exclamation point on this subgenre, we were excused for that unsettling feeling that unseen forces were manipulating our future. Because in that true story, they were.

“The Parallax View” (1974) isn’t the only political picture Hollywood icon Warren Beatty ever tackled. But it’s the most despairing.

A “somebody is recruiting assassins and patsies” tale, it arrived just as Watergate was consuming the country and the Nixon Administration, the scandal’s nefarious perpetrators. The film didn’t make much of a splash, then. But it’s fascinating to dive into it now, after all that’s changed and hasn’t changed in 50 years.

A Seattle political appearance at the famed Space Needle ends with a sitting senator murdered in front of a crowd of admirers and press in an enclosed, high-rise location from which there’s no escape. The alleged shooter, a waiter, doesn’t escape. Chased, this “lone gunman” falls to his death.

Years later, after a “commission” has investigated and settled on yet another “lone nut/gunman” conclusion, a TV reporter present (Paula Prentiss, excellent) shows up, frantic, at the house of her ex-boyfriend, newspaper reporter Joseph Frady (Beatty).

Both of them were there “that day.” But Frady dismisses her paranoia over the number of people who “witnessed” that shooting who have died in the three years since.

“Whoever killed them will try to kill me!”

When she turns up dead, as she expected but he wrote off to her troubled psyche, Frady starts poking around where she wanted him to look, seeking that campaign manager (William Daniels) she was sure had his suspicions.

An attempt on Frady’s own life gets his attention, and brochures and paperwork from this “Parallax” corporation gives him a lead. If only his too-understanding editor (Hume Cronyn) would pay him to keep digging.

“You go expecting these things to happen,” the skeptical Bill notes of Frady’s agenda-driven style, “and they do.”

It’s only after surviving another murder attempt that Frady has the freedom to change his identity and see if he can get closer to this mysterious firm and those who do its dirty business.

Director Alan J. Pakula makes this thriller his warm-up to the details-must-be-accurate adaptation of “All the President’s Men.” “Parallax” is a picture of puzzle pieces, which only Frady seems to have in his head. He’s not sure about those pieces, and not sharing everything he knows.

He doesn’t tell his editor a corrupt sheriff tried to murder him. He never fills anybody in on all he suspects. Frady is ambitious, and sure he’ll be able to break this story all alone.

“I’m dead, Bill,” he says after an attempt on his life allegedly succeeded. “I just want to stay that way for awhile.”

“Parallax” becomes a picture of episodes, one that demands attention and which Pakula guarantees by setting, for instance, a “meet” with an ex-FBI agent (Kenneth Mars) on the kiddie train at an amusement park. A couple of the killings are on camera, and if they’re not shocking now, they must have been then.

The signature image of this picture, the one that sticks with you, is of Frady/Beatty getting a sample of “Clockwork Orange” style “brainwashing” via image-and-word associations projected in a cavernous room as he sits in a comfy chair.

Beatty plays this guy as amoral and guilt free. Reviews that suggest “guilt” is his reason for starting to dig into this story are imposing something on the performance that Beatty doesn’t play.

But there are intriguing cultural artifacts — curiosities of the time — that stand out today. Frady tracks a mysterious piece of luggage onto a plane. A bomb? He boards, without clearing security because you could PAY the stewardess for the flight on BOARD the plane.

Airport security and security around the various senators and senate candidates is laughably lax by today’s standards. That works against the film because even back then this had to seem “off.” The last big killing is almost surreal in the under-reaction of one and all.

That’s how Parallax wants it.

Like all good clockwork thrillers, this one sets up problems and then works the problems. Pakula and Beatty, working from a script by David Giler and Lorenzo Semple, Jr. (Beatty pal and “Chinatown” genius Robert Towne had an uncredited hand in it), reduce the Loren Singer source novel to a string of dilemmas and narrow escapes.

Frady has to hold his own in a fight with a homophobic deputy, get away in a car chase, learn how to be a convincing sociopath from an academic psychologist (Anthony Zerbe, terrific as always) who plays the video game “Pong” with a chimp he’s trained and figure out how to get off an airplane that he’s pretty sure has a bomb on it.

Unlike modern thrillers, this journalist isn’t just after the story. He has a conscience and sees the need to save innocent lives. He uses simple methods to throw a monkey wrench into this “Parallax” outfit’s planned murders.

Having just watched yet another thriller about an ex “special” agent performing almost superhuman feats of cunning, strength and spycraft (“The Beekeeper”), it’s nice to remember the ’70s, when a desk jockey (Robert Redford) might have to learn survival skills on the fly when professional evil-doers with government badges and guns target him in “Three Days of the Condor,” or a lone reporter has to live by his wits when confronted with evidence of organized political killings as he runs afoul of those Parallax alumni who pull the triggers.

In leaving out remedial pauses for explanation, that big scene where the Hero lays it all out for us, “The Parallax View” frustrates as much now as it must have in 1974. Even a close reading leaves one with questions and “What ifs,” then and now.

But nobody in 1974 had a distracting, 5G digital form of crack at their disposal when watching it.

Rating: R, violence, profanity

Cast: Warren Beatty, Paula Prentiss, Hume Cronyn, Jim Davis, Kenneth Mars,

Credits: Directed by Alan Pakula, scripted by David Giler and Lorenzo Semple, Jr., based on the novel by Loren Singer. A Paramount release on Amazon, Netflix etc.

Running time: 1:41