Yoko Ono and John Lennon in 'The U.S. Vs. John Lennon'

In the case of David Leaf and John Scheinfeld's documentary "The U.S. vs. John Lennon," the defendant presents evidence for both sides. On the one hand, there's Lennon as a powerful agent for social change, the man who wrote the unofficial anthem of the anti-Vietnam War movement and put Black Panther Bobby Seale on network TV. On the other, there's Lennon as the not-quite martyr, a private citizen unjustly persecuted by an administration obsessed with stifling dissent. In truth, the former Beatle's introspection and outward actions sometimes worked in synergy, sometimes at cross-purposes.

In an interview with Dick Cavett, Lennon says he considers himself "an artist first and a politician second," an equation "The U.S. vs. John Lennon" gets exactly backward. Commentators from Gore Vidal to G. Gordon Liddy turn up to put Lennon's political beliefs in context, but the film's iPod-shuffle soundtrack reduces Lennon's songs to brief snippets cued with maximum obviousness (e.g. footage of the Watergate hearings scored to "Gimme Some Truth").

There's little sign of the honest ambivalence that made Lennon a great artist, if a questionable spokesman. A tantalizing but typically truncated clip shows the Beatles performing "Revolution" long after they'd stopped giving public concerts, but the film cuts away after Lennon proclaims, "When you talk about destruction, don't you know that you can count me out," muffling the next word he sings, an equally forceful "in."

Making common cause with the yippies and John Sinclair, the White Panther leader who was slapped with a 10-year jail term for giving two joints to an undercover police officer, Lennon was committed if not always cogent, the first in a long line of celebrity activists whose command of the spotlight exceeds their grasp of the issues. At his best, Lennon cut through what "Give Peace a Chance" calls the "ism ism ism" of ideology, formulating boldly simple statements of purpose that energized a movement.

The titular proceeding gets underway in 1972, when the U.S. tries to deport Lennon as an "undesirable alien." Though Lennon's four-year struggle against the Immigration and Naturalization Service occupies relatively little screen time, it's not surprising the filmmakers make it the movie's center, since it's the only proof that Lennon was considered a significant threat to the establishment. Documents show that Nixon's chief of staff, H.R. Haldeman, was kept in the loop, and Liddy says simply, "He was a high-profile figure, so his activities were being monitored."

Lennon won his case, but there's a hint that he got the message all the same: He resisted the yippies' attempts to draft him for a protest concert opposite the 1972 Republican National Convention, and his music turned inward, revisiting the uncomplicated rock 'n' roll of his youth.

Whether Lennon was scared away from politics or just chose self-reflection over public pronouncements, he stepped away from the podium, leaving others to take up the cause. There may not be a moral, but it's a fascinating human story, one that "The U.S. vs. John Lennon" only begins to tell.