A biographical feature detailing the life of Cesar Chavez is long overdue, so many people will welcome the arrival of director Diego Luna’s latest, “Cesar Chavez.”

Luna, who shot to fame as an actor with the Mexican hit “Y Tu Mamá También,” tells the story of the labor leader by looking at the 1960s Delano grape strike and boycott against California growers by the United Farm Workers. Begun in 1965, the strike lasted more than five years, with Chavez eventually going on a fast that drew widespread attention.

Michael Peña, whose credits include Paul Haggis’ “Crash,” David O. Russell’s “American Hustle” and David Ayer’s “End of Watch,” stars as Chavez. And the actor says that he tried to study Chavez’s soft-spoken yet firm oratory. But while his portrayal may be verbally authentic, the gravitas and complexity of the union leader doesn’t come across as well as intended. And that detracts from the overall effectiveness of the film.

It’s not entirely Peña’s fault. He has to try to keep up with two high-powered actresses: America Ferrera as Chavez’s wife, Helen, whose loyalty to the cause was sorely tested, and the volatile Rosario Dawson as Dolores Huerta, the co-founder of the National Farmworkers Association, which later became the United Farm Workers.

Dawson, in particular, shines as the fiery labor leader who gave up a teaching career to help organize workers. And she’s a scene-stealer.

Luna also creates a fictional, composite character to represent the leader of the growers who opposed Chavez’s efforts to organize workers. In the movie, he’s called Bogdonovitch, and he’s played by the usually excellent John Malkovich. But in “Cesar Chavez,” Malkovich doesn’t have much to work with when considering the script by Keir Pearson and Timothy J. Sexton. He’s more of an archetype of privilege rather than a fully fleshed-out character.

While much of the movie focuses on the tireless efforts of Chavez to organize workers, Luna deliberately tries to avoid deification of the labor leader by showing how much his work interfered with his family life. One of his sons, in fact, grows alienated over Chavez’s long absences.

And perhaps that’s the point: Although undoubtedly a great leader who struggled to build a nonviolent labor movement, Chavez was also a normal, simple man with flaws. And even those kinds of men and women can do exceptional things, especially if they stand together for justice. Or as Chavez and Huerta would say, “Sí, se puede.”