A former Fox News producer says they had a name for it; the network’s style, the “stories” favored there and the edict they were given from on high.

“We used to call it ‘Riling up the crazies,'” Joe Muto remembers in the documentary “Divide and Conquer: The Story of Roger Ailes.”

And that’s what Roger Ailes, the Nixon campaign media specialist who became first a GOP kingmaker, and then the king of cable news, did everywhere he went.

“Divide” is a damning film, with just enough new material to entice the curious.

Before he was drowned in a tidal wave of sexual harassment lawsuits right in the middle of the 2016 Republican presidential nominating convention, with his friend and Fox-fluffed candidate Donald J. Trump about to have his GOP coronation, Ailes figured out which hot buttons to push and repeatedly pushed them, forever dividing an America eager to be re-segregated and doing it through the power of TV.

Director/interviewer Alexis Bloom found a seemingly endless parade of former colleagues, journalists who covered Ailes and ex-employees to talk about his “Divide and Conquer” view of America. Even those hired to help him “manage” the abuse and harassment crisis that brought him down speak out.

You can say, “They didn’t exactly succeed in that task, did they?”

Before his fall, Ailes “made conspiracy theories mainstream” when he agreed with their politics, perfected the art of the smear by TV political commercial and gave America’s angriest and oldest a TV channel where every fear they want to believe in is given credence, every hatred they’ve harbored for life is justified.

Bloom, the Brit who made “We Steal Secrets: The Story of Wikileaks,” spends 100+ minutes exposing Ailes’ secrets, methods and meanness in a movie that is required viewing for anybody anxious to see the feature film on Ailes that’s in pre-production. John Lithgow is set to play Ailes, with Nicole Kidman, Charlize Theron, Margot Robbie and Alice Eve set to play assorted Fox News members of his “harem.”

Bloom takes us back to Ailes’ childhood in Warren, Ohio, son of a union-hating union man, fierce debater and high school charmer. The accomplished character actor Austin Pendleton (“Searching for Bobby Fischer”) was a classmate and paints a portrait of the teen who became the man.

“Roger lived his whole life in fear,” Pendleton asserts. Hemophilia did that to him, and made him the greatest “chicken hawk” of them all (no military service). This personal fear “allowed him to understand the fears of other people,” and to sell those via Fox News, 24/7.

Early colleagues remember Ailes’ angling his way up the ladder at Philadelphia’s syndicated “Mike Douglas Show” in the ’60s. A certain presidential candidate appeared on the show in 1968, and Ailes made his move.

“The only person I ever saw Roger hit on was Nixon,” a fellow producer jokes. He became Nixon’s media guru, staging fake “town hall” meetings with pre-selected questions, shepherding Nixon’s TV campaign into the White House.

Ailes had the idea of a TV “network” of sorts — a means of “bypassing the critical press,” for Republicans — during the Nixon years. He wasn’t able to make that come to pass until the ’90s with Fox.

In the intervening years, he made his name as a “king maker,” masterminding media image campaigns for generations of Republicans who wanted to go to Washington. The effort it took to get the effete Mitch McConnell elected to the Senate from Kentucky is worth a laugh or two.

The TV mogul’s former star, Glenn Beck, who has “seen the light” and renounced his divisive ways, psychoanalyzes his late employer as a man “with a real terror inside him…wanting to be liked.”

“It’s easy to make somebody into a monster,” says Beck, who admits he used to “perform” on Fox, and plainly still is performing. “It’s hard to see that you’re on that path, too.”

Ailes bugged the offices and even the elevators at Fox News, kept personal files on staff and hired a private investigator, Bo Dietl, to hunt for dirt on his enemies, a man who became the classic “Friend of Roger” Fox News guest “expert.”

An actor reading Ailes’ writing spits out rage at “The New York and Hollywood elites,” something he knew he shared in common with his viewers.

“Roger always knew the lowest common denominator for people,” more than one former employee says, in various forms.

The sexual harassing? Casting couch sessions with aspiring reporters, consultants and guests? “He picked on people who needed him, not just women,” but he was hunting for validation via sex, much of the time. “He needed a harem.”

Ailes learned his TV political “optics” from Leni Riefenstahl’s “The Triumph of the Will,” had a hand in every significant GOP victory from Nixon to Trump, and propositioned, bullied and coerced (often ruining those who turned him down) scores upon scores of women starting with his earliest days in TV.

Much of this isn’t new or “news,” as we’ve already heard from many of these voices — despite hundreds of millions in settlements, with the non-disclosure agreements that go along with that.

The early years, a 1960s profile by Mike Wallace, are balanced with telling later TV interviews (having a chuckle with Charlie Rose about drinking and womanizing TV journalists), all depicting a Hitchcock shaped “Master of Offense.”

Montages of the hate-filled bigotry Fox poured onto its shows about Barack Obama are hysterical, in every sense of the word.

The Willie Horton ad, the Clinton-Lewinsky Scandal, the first revelations about Fox star Bill O’Reilly’s loofah madness (in 2004), the red letter dates in Ailes’s public life get their moments in Bloom’s film.

But so do his efforts to manipulate the politics of Cold Harbor, New York, where he built a mansion, bought the tiny local newspaper and tried to bully one and all into submitting to his will and his hand-picked candidates to run the place.

That didn’t work out.

Several of those interviewed note how Ailes “needed enemies” to succeed, to drive him. And he did. That’s exactly how he earned his reputation for dividing America, the crux of Bloom’s film (opening Dec. 14).

But one former “enemy” remarks how glad she was when it all came apart “while he was still alive.”

And others marvel at how Fox is exactly the same attack machine it was the day he was ousted, pointing to the America and the government Ailes left behind.

“If (Trump) hadn’t been real, Roger Ailes would have created him,” onetime Fox producer Muto cracks.

MPAA Rating: unrated, sexual discussion, profanity

Cast: Roger Ailes, Glenn Beck, Alyson Camerota, Pat Buchanan, many others

Credits: Directed by Alexis Bloom.  A Magnolia/A&E Indie Films release.

Running time: 1:47