“Jackie”

Rated R (1:40)

***1/2

Opens today

“I’m not the first lady anymore,” Natalie Portman says in the clenched and wheeling biopic “Jackie.”

Well, no, in the aftermath of the assassination of President John F. Kennedy on Nov. 22, 1963, his widow — played by Portman with transfiguring intensity and focus — cedes her official position, her place in the White House and in the land.

But there is not one instant in Chilean director Pablo Larrain’s daring psychological portrait in which the actress isn’t that famous first lady — the elegant woman with the breathy locution, the prep school poise and, after the horrible car ride along Dallas’ Dealey Plaza, the blood and brain matter splattered on her Chanel suit.

Shot in close-up, the camera never far from Portman’s face, “Jackie” is anything but a traditional biopic. Flashing back and forth in time — the televised guided tour of the White House that Jacqueline Kennedy led in 1962, the magazine interview she held in the family’s Hyannis Port, Mass., home just a week after her husband’s death — the film plays with history and memory, fact and speculation.

It is a fever dream of a movie, tracking its subject as she tries to maintain control, maintain her composure and her sanity, and as she tries — shellshocked, quaking with grief, but also fiercely determined — to shape and secure her husband’s legacy.

Working with a script by Noah Oppenheim, director Larrain reclaims some of the iconic images of the events surrounding the assassination: the first lady stepping off Air Force One, waving, at the Dallas airfield; the funeral procession; the veiled mother grasping the hands of her two young children.

Some of the casting works well: Caspar Phillipson, chiseled and familiar, as JFK; Greta Gerwig as Nancy Tuckerman, Jacqueline Kennedy’s aide and confidant; Max Casella as Jack Valenti, the more-than -a-little-sycophantic assistant to President Lyndon Johnson. Peter Sarsgaard gets the thankless task of trying to bring Robert Kennedy back to life, doing so with a furrowed brow but without much of the physical bearing, or manner, of JFK’s brother, the attorney general.

And what to make of Billy Crudup as “The Journalist,” a composite character, cobbled together with bits of Kennedy chronicler Theodore H. White and other reporters who met with the grieving Jackie in the weeks following the president’s death?

Why is Crudup’s tie loose, the top button of his shirt unfastened? Is that an artistic decision on the part of the actor or the director? A historical detail? Whatever it is, it’s a distraction. And there’s something about the mix of commiseration and confrontation in Crudup’s approach that rings wrong.

Still, as The Journalist and The Widow talk, framed by great windows looking onto trees and lawn and water, Jacqueline Kennedy’s mission — to seize the narrative, to fix her husband’s place in the annals of the nation — becomes ringingly clear.

And it is a matter of record that Jacqueline Kennedy suggested to White, writing his story for Life magazine, that he compare Kennedy and his administration to that of King Arthur’s and the fabled Camelot. “Camelot,” the Lerner and Loewe musical, was big on Broadway just then. And “Jackie,” a crystal shard of biography and myth, lets the original cast recording of Richard Burton, grandly intoning the title song, fill the air, the darkened room: “Don’t let it be forgot, that once there was a spot, for one brief shining moment, that was known as Camelot.”

Audacious. And exactly right.