"Protocols of Zion" is either enigmatically or provocatively titled, depending on your level of familiarity with its referent, the Protocols of the Learned Elders of Zion. Written in the late 19th or early 20th century, probably by agents of Czar Nicholas II to quell the impending revolution, the Protocols is a fraudulent document purporting to be written by a group of Jews laying out a plan for Jewish world domination. Although the screed has long since been debunked as a malevolent hoax, "the lie that won't die" has lived on, fueling and being fueled by anti-Semitic groups and cultures for the past century.

Indeed, one of its most recent iterations was the theory, floated just after the attacks of Sept. 11, 2001, that the Jews who worked in the World Trade Center were told not to go to work that morning. As outrageous as the story was, it gained surprising traction, a fact that inspired filmmaker Marc Levin, who has won awards for his documentaries about gangs, politics and the criminal justice system, to examine just how far the Protocols have informed and infiltrated the culture.

Taking his camera out into the streets of New York and beyond, Levin begins a series of freewheeling and revelatory conversations, many of which would be amusing were they not so appalling. At one point, a group of black demonstrators talks about living in "Jewmerica" and casually remarks that New York's mayors have "always been Jewish." ("What about Giuliani?" Levin asks. "See? Jew-liani!" one responds.) Later, the filmmaker is given a tour of the West Virginia warehouse belonging to the National Alliance, a white supremacy group whose clean-cut chief insists the white race is "Earth's most endangered species."

From Henry Ford and the radio demagogue Father Coughlin to the prime minister of Malaysia -- who in 2003 delivered a speech larded with anti-Semitic paranoia -- and "The Passion of the Christ," Levin explores the myths expounded in the Protocols and the ways in which they've been perpetuated by each era's political, religious and cultural leaders. (There's a funny and very revealing scene in which the filmmaker tries to get a group together in Los Angeles to talk about Jews in Hollywood the night before "The Passion of the Christ" comes out; a round robin of avoidance ensues between Levin, Norman Lear, Larry David and Rob Reiner.) Throughout, Levin invokes his own family history, especially his father, who as a self-described atheist has been an outspoken activist and artist on behalf of civil rights and progressive causes.

"Protocols of Zion" is most effective as memoir and comes most alive when Levin and his father share what it has meant to each of them to be a Jew; as an onscreen character, Levin comes across as sometimes ambivalent, sometimes freaked out, but always deeply humanist. The movie goes off the rails only when the filmmaker inadvertently legitimizes the Protocols' loony philosophical heirs by interviewing a New York medical examiner and a widow about the remains of one of 9/11's Jewish victims. In going to such great lengths to correct the racists, bigots and haters of the world, Levin gives them way too much credit.

Protocols of Zion (93 minutes at Landmark's E Street Cinema) is not rated. It contains brief profanity.