Just in time for the fiftieth anniversary of the historical event it faithfully recreates, Ava DuVernay’s “Selma” situates Martin Luther King Jr.’s March, 1965 Alabama voting-rights campaign within the larger context of the national politics of the day. The compelling docu-drama can serve as a valuable educational tool but is first and foremost an emotionally powerful narrative.

In dealing with King, DuVernay and screenwriter Paul Webb follow the scheme that Steven Spielberg used in “Lincoln.” They don’t attempt a full biography—something that would certainly require far more time than a feature-length film can offer. Instead they focus on a single paramount event in the great man’s career, using it to illustrate his tactical skill in employing the tools at his disposal to work toward a desired end. The genius of “Selma,” as with Spielberg’s film, is that it avoids portraying its hero as some sort of plaster saint, instead showing him to have been a man of eminently practical bent, personally flawed in some respects but a political tactician of the highest order striving to achieve a great goal, and often compelled to prod others to follow his lead.

It’s that latter point that has led to some criticism of Webb and DuVernay’s presentation. Little issue can be taken with the film’s overall portrayal of the events in Alabama, although there is necessarily some elision and omission. After what amounts to a prologue juxtaposing King’s receipt of the Nobel Peace Prize in 1964 with the Birmingham church bombing of 1963, the focus shifts to what becomes the central issue of the scenario: the barriers blacks faced in trying to register to vote in the state despite the passage of the 1964 Civil Rights Act, succinctly sketched in the humiliation of an African-American woman, Annie Lee Cooper (Oprah Winfrey), by a county clerk. And King decides to take up the fight, resulting in three marches—the first brutally suppressed, the second aborted, and the third continuing the more than fifty miles to the state capital at Montgomery. DuVernay stages each of them expertly, with the viciousness of the first, the confusion attendant to the second and the euphoria of the third all splendidly caught.

What’s exceptional in all this is how the filmmakers portray King’s arrival in Selma, along with the degree of calculation they’re willing to ascribe to him. The fact that he and his associates from the Southern Christian Leadership Conference weren’t joyously received by some members of the Student Nonviolent Coordinating Committee, who had been organizing the movement until then, isn’t overlooked; nor is the fact that King frankly presents himself as needing to provoke confrontation with local authorities in order to gain the press coverage, and thus the political clout, he needed. (Having recently suffered a setback in one Georgia campaign, when the police had refrained from violence, he pointedly asks whether he can depend on a nasty response from the Selma sheriff, and is pleased when he’s told he can.) But while doing justice to the strategic elements of King’s work—even touching briefly on the role played by King’s old rival Malcolm X (Nigel Thatch) who, in this version, arranges with Coretta Scott King (Carmen Ejogo) to be used as a contrast to her husband’s peaceable approach—the film also manages to personalize the story effectively at street level, especially through episodes concerning elderly Cager Lee (Henry G. Sanders), who endured the murder of his son (Keith Stanfield) in the course of the campaign, and of Northern minister James Reeb (Jeremy Strong), whose killing drew national outrage.

Where “Selma” has caused controversy is in how it situates these Alabama events—which include the intervention of Governor George Wallace—within the context of Washington politics. It rightly points out President Lyndon Johnson’s reluctance to propose a Voting Rights Act as quickly as King would have liked, but debate has arisen over the extent to which the men disagreed. The film portrays the president as so infuriated by King’s attempt to force his hand on the issue that he goes so far as to consult FBI Director J. Edgar Hoover about smearing him, and going ahead with the legislation only after negotiations with Wallace have proven fruitless. Figures from Johnson’s administration have complained about that interpretation, arguing that the president’s decision was merely to postpone proposing legislation until chances of passage were better, and that he and King were actually working together, with the Selma campaign even part of their joint effort. The controversy won’t be settled quickly or definitively, of course—which ironically gives “Selma” even greater potential as an educational tool, if it stimulates discussion rather than simply being accepted as gospel. And at least it can serve as an antidote to “white savior” Civil Rights pictures like “Mississippi Burning,” which typically relegate the role of African-Americans to the rear of the cinematic bus (while extolling the FBI).

What there shouldn’t be any debate about, moreover, is the extraordinary quality of David Oyelowo’s performance. He doesn’t look all that much like King, but what’s important is that, just as Daniel Day-Lewis managed in “Lincoln,” he brings real humanity to an icon—and that he captures to a remarkable degree the cadences of his speech, a talent that makes the excerpts from King’s speeches incredibly powerful and moving. One can quibble about Tom Wilkinson’s turn as Johnson, which while capable doesn’t entirely transcend caricature, and Tim Roth’s as Wallace, of which the same can certainly be said. And Dylan Baker seems all wrong as Hoover, while Martin Sheen, after all those years as the principled president on “The West Wing,” comes off too much on the money as the federal judge who lifts an injunction prohibiting the final march.

On the other hand, Winfrey, Stanfield and Sanders hit home emotionally, and Ejogo subtly portrays a wife who’s loving and supportive but also concerned and even a bit suspicious about her husband. Other notables in the Civil Rights movement—Fred Gray (Cuba Gooding, Jr.), John Lewis (Stephan James), Andrew Young (Andre Holland), James Bevel (Common), Ralph Abernathy (Colman Domingo), Hosea Williams (Wendell Pierce), Bayard Rustin (Ruben Santiago-Hudson), Amelia Boynton Robinson (Lorraine Toussaint), Diane Nash (Tessa Thompson), James Forman (Trai Byers)—are also nicely etched. And though the film is hardly massively budgeted, it’s been well served by its technical team, with Mark Friedberg’s production design, Kim Jennings’ art direction, Elizabeth Keenan’s sets and Ruth E. Carter’s costumes evoking the period without exaggeration and Bradford Young’s expert cinematography similarly doing the job while not calling attention to itself.

As history “Selma” may cause some controversy, but as a fact-based drama it’s exceptionally fine.