Director Ava DuVernay’s sweeping drama about a pivotal chapter of the American civil rights movement quickly became one of the most controversial films of the year, with one debate dominating much of the public discussion: whether “Selma’s” depiction of the relationship between the Rev. Martin Luther King Jr. and President Lyndon B. Johnson was historically accurate.

Supporters of LBJ — including Mark Updegrove, the director of Johnson’s presidential library, and Joseph A. Califano Jr., Johnson’s top assistant for domestic affairs — have expressed outrage at what they say is a combative and obstructionist portrayal of the former president, insisting that Johnson was a dedicated advocate for the civil rights movement.

But the film’s backers contend that the movie’s representation of Johnson is nuanced and fair. Many have also applauded DuVernay’s choice to break from Hollywood’s familiar “white savior” formula (see: “To Kill a Mockingbird,” “A Time to Kill,” “Amistad,” “The Help”) by focusing instead on the role of black civil rights leaders.

DuVernay has said that her goal was to capture the complexity of every character in the film, including King, who is hardly portrayed as a flawless saint: the movie includes a wrenching scene in which he is forced to acknowledge extramarital affairs after the FBI sends an audiotape of a passionate tryst to his wife, Coretta. (And yes, the FBI really did mail incriminating tapes to the family in its attempts to discredit King.)

Beyond the Johnson controversy, the film sticks closely to well-established facts. When certain artistic liberties are taken — for instance, the movie shows 26-year-old Jimmie Lee Jackson shot dead in a restaurant by white police officers, while in reality Jackson died days after the shooting — they tend to be of minor consequence. And the re-imagining of King’s speeches is particularly impressive: King’s estate did not give permission to use his actual words, but “Selma’s” writers were nonetheless successful at capturing his eloquence and intent.

Fact-checking the Best Picture nominees: