The loathsome Roger Ailes, notorious as a former Nixon apparatchik and veteran CEO of the stridently mediocre Fox News channel, became even less fragrant in 2016 when the open secret of his sexual harassment became an open non-secret. The channel’s former anchor Gretchen Carlson successfully filed a lawsuit against him, revealing that he made sexual advances to her and other women at Fox; their careers would be advanced (or cancelled) at his seedy whim. Carlson’s courageous lawsuit was supported by six other women and the 76-year-old Ailes’s own boss, Rupert Murdoch, fired his underling, who died a year later.

This gruesome soap opera of misogyny and reactionary politics has already been turned into a Showtime TV drama, The Loudest Voice, with Naomi Watts as Carlson and Russell Crowe as Ailes – and now it is a movie directed by Jay Roach and written by Charles Randolph, with Nicole Kidman as Carlson and John Lithgow horribly plausible and latexed up as her bloated old sex-criminal employer. Charlize Theron is Fox News presenter Megyn Kelly, who infuriated the Fox News fanbase by challenging Trump on his anti-women attitudes before the election, and Margot Robbie plays Katya Pospisil, a fictional composite of all the younger women who were abused. She is the “Christian influencer” on Instagram who figures she can get ahead at Fox, and submits, almost in a dream, to the humiliation required.

It is a strange film in some ways, speckled with powerful, insightful moments but also with some strained acting, pulled punches and fudged attitudes, unable to decide if its heroines are compromised through having been loyal Fox staffers. Ailes is the obvious villain but Murdoch (still alive, with lawyers and power in the media world) is almost presented as the good guy, finally intervening to create a happy ending and played in cameo by Malcolm McDowell. Despite the film’s title, the Carlson/Ailes lawsuit was not a bombshell in the way the Harvey Weinstein revelations were a year later. This may have been because Ailes’s accuser was no feminist, and was for years fully on board with the aggressively boorish and sexist attitudes of Fox News.

As for Kelly, the film uses some narrative sleight of hand to suggest that she joined forces with Carlson, when it fact she appears to have limited her support to reporting her own harassment from Ailes in an internal investigation.

Where Bombshell succeeds is in showing how the predatory and sinister abuse plays out in the corporate environment – in bullying. The film shows that sexual harassment and bullying are not separate issues but part of the continuum of coercion. It sketches out a queasy scenario in which a younger female journalist is taken out for a drink by a male boss who brutally asks for sex in return for career advancement, and the film shows how the aghast woman’s instinct is to forgive this man, to pretend it isn’t happening, even to apologise: “I’m sorry if I’ve given you the impression that our relationship could be anything but professional…”

Carlson and Kelly are the male-bully victims and there is a truly toe-curling scene in which Carlson, already demoted to an afternoon slot for complaining about on-air bantz from her grisly male co-hosts, presents a “no cosmetics” show. Ailes crassly blunders into the studio and shouts at her in front of the crew, screaming that no one wants to see a middle-aged woman sweating. Humiliated, Carlson can only riposte: “Thank you for the advice!” — and Kidman powerfully shows her rage.

I found Theron’s performance as Kelly a little studied and mannered, but again she powerfully shows the same power dynamic. When male inadequates no longer find a woman in the workplace attractive or susceptible to condescension, they bully and demean her, and Ailes revoltingly allowed Donald Trump to do this to Kelly via Twitter, partly because Trump was a ratings star and partly because Ailes not-so-secretly agreed with the future president. The unexpressed irony of this movie is that the president, a serial non-respecter of women, detonated his own explosion of cynical bigotry. The rubble has yet to be cleared away.