The American Indian Movement, almost forgotten today, captured the public’s interest in the 1960s and ’70s with a series of high profile protests against the U.S. government. John Trudell emerged as one of the leaders of AIM in the late 1960s. Starting in 1969, the group occupied the island of Alcatraz for more than a year, and in 1973 seized the Bureau of Indian Affairs in Washington for more than a month. Mr. Trudell was tangentially involved in a series of encounters with the federal government in South Dakota, culminating in the notorious Leonard Peltier incident where two FBI agents were killed in a standoff with Indian activists. Along the way, Mr. Trudell amassed a 17,000-page FBI dossier, one of the longest ever.

So as documentary subjects go, Mr. Trudell is not a bad choice. And the eponymous documentary “Trudell,” by filmmaker Heather Rae, provides a thorough and sweeping overview of the man’s life.

By the early 1980s, AIM’s momentum was waning and Mr. Trudell found himself adrift after his pregnant wife and three children died in a tragic house fire. (Without a shred of proof, the film irresponsibly stops just short of suggesting that his family was actually murdered by the FBI.) He managed to reinvent himself as poet and musician during this time, and along with interviews and historical footage, it’s Mr. Trudell’s own music that anchors much of the film.

For the uninitiated, Mr. Trudell’s music is definitely novel; it combines spoken word, Native American chants, and drums with blues rock and New-Age. The admixture isn’t as bad as it sounds, though tolerances will vary widely depending on one’s sympathy for Mr. Trudell’s politics and stream-of-consciousness tautologies.

While “Trudell” does a decent job of recounting the historical details of his life, the film’s intentions are unforgivably one-dimensional. When Mr. Trudell blames European countries for the poor treatment of Native Americans by literally blaming the entirety of “Western Civilization,” or says celebrating Columbus Day is like celebrating Osama bin Laden Day, the filmmakers fail to ask hard questions and the film suffers.

This is doubly true of the film’s treatment of AIM’s history. Despite moral authority the group has earned from the overwhelming injustice experienced by Native Americans, AIM squandered much goodwill with their unworkable idealism and misguided protest actions. And yet the film does not once offer a critical perspective on Mr. Trudell or his work.

Instead Ms. Rae trots out a string of vapid celebrities to affirm their solidarity with Mr. Trudell’s struggle. Robert Redford compares him to the Dalai Lama. Renowned Canadian-Indian actor Gary Farmer compares him to Socrates. Bonnie Raitt waxes nostalgic about his appearance at a No Nukes benefit 25 years ago. And Kris Kristofferson seems convinced that the FBI really did kill his family.

As a vehicle for examining the plight of the American Indian in a modern context, Mr. Trudell’s life could be an excellent starting point. But “Trudell” is too busy heaping undeserved praise on this complex and contentious man.