I might have a new favorite movie line. It is deep in the middle of Jackie, Natalie Portman’s almost one-woman show about truth, fiction and Jackie Kennedy in the days after the assassination of her husband, John Kennedy. “Jack would walk into the desert alone to let himself be tempted, but he always came back to us,” Portman tells a journalist, played by Billy Crudup, as she sets up a sly bit of myth-building about her not-so-constant mate.

“And I don’t smoke,” she adds, taking another drag on her ever-present cigarette. (Apologies to Stanton Glantz, and the Center for Tobacco Control Research and Education.)

That “I don’t smoke” could displace the kicker from John Ford’s The Man Who Shot Liberty Valance—“When the legend become fact, print the legend”— which has been on top my list, and is probably the best screen line to date about a public preference for fiction over fact. In Liberty Valance, the fiction had to do with heroism and the Old West. In Jackie, it is a Camelot fable that grew, with Jackie’s help, around John Kennedy’s short presidency.

Like Ford’s famous Western, Jackie, directed by Pablo Larrain and written by Noah Oppenheim, isn’t out to destroy the myth, but rather to plumb its depths. While plenty of actors — including Crudup, Peter Sarsgaard and Greta Gerwig — populate the film, the heavy lifting falls to Portman. She is there from beginning to end, often in close-up, dancing, like the ballerina in Black Swan, between bitter self-doubt and a mesmerizing stage show that was the Kennedy White House.

There will be arguments about her accent — Portman works hard to capture a complicated old-school debutante sort of thing. But everything about Jackie is deliciously complicated, right down the logistics at Monday’s Toronto festival press screening. It found a spill-over crowd of 550 viewers at the Scotiabank 1 theater waiting, as festival officials delayed the movie until three people who were saving seats for friends locked outside finally gave them up to standees who had already gotten in. It all worked out, as did Jackie Kennedy’s grandest production, her husband’s state funeral, which brings a grand set piece to a film that otherwise barely looks away from Portman.