The Chicano labor leader César Chávez can now join Mahatma Gandhi and Nelson Mandela in the pantheon of heroes whose world-altering achievements are dutifully recounted in timid, lifeless films any substitute can pop into the school DVD player when the regular history teacher is out with the flu.

With César Chávez, Mexican director Diego Luna, who co-starred in last year's space fantasy Elysium and explored bi-curiosity with Gael García Bernal in Y Tu Mamá También, seems less interested in making human and revealing cinema than a live-action inspirational poster. When his Chávez stands at the lectern, Luna shoots lead actor Michael Peña from the shoulders up and from the side, gazing beatifically at the awed crowd.

Curiously, though, this Chávez's followers are few, just two or three dozen stout men in straw hats. Take away the ocher sunlight of California's Central Valley (though the film was shot in northwestern Mexico), and the scene could be a metro section photo covering a local city council race. The sparse tableaux speak to the intimacy of Chávez's activism, but also suggest the film's inability to capture the scope of its subject's influence and accomplishments.

César Chávez focuses on the famed 1965–1970 grape strike that won higher wages and better working conditions for Mexican- and Filipino-American migrant laborers. As an early scene shows, the five-year campaign was instigated by a group of Filipino workers. Chávez bridged the Asian-Latin American gap and added to their strike's span by rallying Chicanos to their cause.

Occasionally, it's possible to get a sense of Chávez as a man of his time — specifically, as one player in the internationalist Third World movement of the 1960s, which emphasized commonalities between oppressed racial groups around the world. "They play the races against each other," sermonizes Dolores Huerta (Rosario Dawson), a prominent labor leader who would eventually found the United Farm Workers union with Chávez. (Not that you'd learn that from this film, which lectures against Latin machismo and yet almost entirely expunges women's contributions to the campaign.)

Keir Pearson's script plays out like a highlight reel of the grape strike. It fails to effectively dramatize the slow process of converting ordinary laborers to the workers' cause and of selling the boycott to everyday consumers. What little narrative propulsion there is comes from upsetting scenes of overt racism, as when angry white farm owners wantonly shoot at Mexican-American protesters or run them over with pickup trucks.

Luna's Chávez is a Catholic saint, not just in his religious faith but also in his dedication to the idea that mortification of the flesh is the key to a paradisiacal future. The film begins with Chávez leaving his cushy job as the national director of a Latino civil rights group, where he wears a suit (but no tie) to work; he's soon toiling in the fields despite his chronic backaches to gain the trust of the workers. Moving his wife and eight children into a three-bedroom house in the farm towns also means holding back his own kids' prospects to provide better opportunities for the farm workers' children. "The kids here are idiots," complains his son Chato (Maynor Alvarado), suddenly the target of anti-Mexican slurs.

But Luna's Chávez isn't a man of contradictions. Nor is he a man of action. He merely suffers: beatings by angry white farm owners, unkind words from an increasingly rebellious Chato, agony from spectacular protests like a 25-day fast and a 300-mile march. The film doesn't seek admiration for his deeds or his force of will, only sympathy for enduring the kind of physical pain the Jackass crew used to undergo every week for MTV.

The careless diminishment of every other character that isn't Chávez — including wife Helen, played by an utterly wasted America Ferrera in a grape-sized role — might be worth overlooking if the film provided any insights into its subject. There are intimations of suggestions of allusions to the media-savvy ideologue that Chávez actually was. (As the rightwing press is still fond of pointing out, the union man occasionally agitated against immigration, fearing that scabs would undermine the effectiveness of his strikes, and even reported a few undocumented workers who wouldn't join his campaigns to INS.)

But the film, which earned the seal of approval from the cautious Chávez estate by collaborating with the labor leader's heirs, is only interested in celebrating a hero. "We're fighting for basic human rights," the character says at one point, a line that matches its speaker in its bland, abstract sincerity. Peña, who's proved himself a minor comic genius in 2012's End of Watch and a season-long guest turn in HBO's Eastbound and Down, is utterly undone by Pearson's underdeveloped screenplay. He just seems sleepy.

President Obama evoked some political magic when he declared, "Yes, we can" — a slogan borrowed from Chávez ("Sí, se puede"). But Peña's disinterested delivery reduces that thrilling promise — that everyday citizens have the power to create a better future for ourselves — into an interjection, a noun and a verb. Watching his life-size cardboard cutout of Chávez shout, "Yes, we can," I was moved, but only to wish that one of the things "we" can do is to make a resonant, dramatically rich film about a leader who forcefully but nonviolently bent the arc of the moral universe toward justice — which this inoffensive cow pie most certainly isn't.