"I will not sneak out the back door." Noah Oppenheim's script has Jackie Kennedy grieving not just her husband's murder, but the abrupt end of their work in the White House. Opening on the day of Trump's inauguration, Jackie holds a mirror to the puzzlement and fear of observers in 2016: the Obamas depart graciously, followed by the unknown.

Will the film land an auspicious Best Actress Oscar for Natalie Portman's vanishingly accurate portrayal of the former FLOTUS? Jackie may be overlooked in the tide of La La love that is overwhelming all in its wonderfully choreographed path. Portman was victorious at the Critics' Choice Awards, as were the teams nominated for Best Costume Design and Best Hair and Makeup - indeed, the score and costume design are up for Oscars too. But I'm hoping this piece won't be remembered as style over substance, because that's what its lead character fears her fate may be. Legacy is the entire theme of Jackie, wherein a woman invites America's TV cameras into its corridors of power, acquires artefacts because of their historic significance, shows her fluency in the biography of Lincoln... and describes the look on JFK's face seconds after he was shot, soon taking it upon herself to curate his memory.

I like that the script goes there. Our director Pablo Larraín leads us through those storied halls giving them a regal grandeur, to a massive graveyard extending into opaque mist, to a spaceless washroom in which Portman emits shocked sobs and studies her bloodstained hair. All the while, she is stridently in centre-frame. A mere skilled impersonation couldn't bear that scrutiny - Portman shows the steel behind that airily affected vocal tone, and the ruthless editorial streak when facing off against Billy Crudup's journalist. Assisting the thematic expansion from biopic-personal to universal is Larraín's realisation of the structure: a Malickian free-flow of time avoids a didactic made-for-TV chronology, and enables emotional connection by linking events in other ways. It is an intense, visually rich experience, with several fine performances (refreshingly restrained Richard E Grant, John Hurt is reliably faultless, Greta Gerwig all big-sisterly consolation as Jackie's devoted aide, and Crudup's restrained infuriation at his interviewee's evasiveness is expressed only as a tiny twitch of the jaw).

The use of 16mm stock coheres with familiar period footage, forging a bold, fragile and believable look, and the visual sumptuousness is matched by Mica Levi's score - the orchestral arrangement is sometimes august as if written by the court composer to JFK's Camelot, sometimes blurrily dissonant, but always mixed high, as if the orchestra is right behind the screen. Some have asked how historically accurate the film is, pertinent when earth-shattering moments are captured forever on YouTube. But the point is, Jackie is perceptibly editing the story for what was formerly 'her' public - she's concerned about her work having been vanity or in vain, and that curatorial function is her role now. The priest gets an unexpurgated version of her inner turmoil, and the journalist gets "Don't think for one second I'm going to let you publish that". I think it's great storytelling with a very slight story, and Portman and Mica Levi would be justified in receiving their Oscars in February.