The political broadsides that have arrived in theaters nearly every week this year may have been manna for political junkies, but they've been painful for movie fans; few of these films , from a technical or artistic standpoint, have been any good. "Going Upriver: The Long War of John Kerry" is a gratifying exception, having been made by a seasoned documentary filmmaker with a compelling story to tell.

George Butler is a close friend of John Kerry and an unapologetic Democratic partisan as far as Kerry's presidential bid goes. But "Going Upriver" manages to transcend its immediate subject to become a fascinating, often wrenching portrait of one of the most divisive and divided eras in American history.

Focusing briefly on Kerry's upbringing in Massachusetts, his years at Yale and his decision to fight in Vietnam, Butler reserves his deepest interest for Kerry's involvement with Vietnam Veterans Against the War, the group he represented before the Senate Foreign Relations Committee in 1971. That testimony is the stirring high point of "Going Upriver," which puts into emotional and historical context such recent controversies as Kerry's actions on the Swift boat he commanded, the medals he earned in the course of that command, his statements on behalf of his fellow antiwar activists and his solemn, symbolic gesture of throwing his medal ribbons over a fence and onto the steps of the Capitol.

Butler clearly sees Kerry's service in Vietnam, as well as his postwar activities, as evidence of moral courage, and he is amply supported by the testimony of Kerry's fellow Vietnam veterans, from members of his Swift boat crew to former senator Max Cleland (D-Ga.). But "Going Upriver" is far more than just a persuasive rejoinder to claims that Kerry inflated his Vietnam record and defamed the military when he returned. Using extraordinary footage that Butler himself collected at the "Winter Soldier" hearings in Detroit in 1971 -- when more than 100 veterans compared memories of atrocities they committed or witnessed in Vietnam -- the filmmaker depicts the pain and betrayal of an entire generation.

Butler was also on hand a few months later when Kerry led the VVAW's march on Washington, a five-day demonstration whose climax was the 27-year-old's assured, eloquent and moving testimony before the Senate committee. It's a riveting moment, made all the more so by the fact that Kerry was probably setting his own political career back by speaking out. (Nixon was so threatened by Kerry's Kennedy-like persona that he ordered Charles Colson to "destroy the young demagogue before he becomes the next Ralph Nader." Colson in turn enlisted Vietnam veteran John O'Neill to debunk Kerry. O'Neill recently reemerged as part of the Swift Boat Veterans for Truth campaign questioning Kerry's account of his service in Vietnam.)

"Going Upriver" occasionally waxes hagiographic, such as when Kerry's Yale classmates remember where he was when John F. Kennedy was shot, and during a celebratory montage of Kerry family pictures during the closing credits. (Butler did not interview Kerry for the film.) But for all his personal and partisan bias, Butler -- who directed such terrific documentaries as "Pumping Iron" and an obscure but wonderful film about hunting called "In the Blood" -- marshals historical footage, still photographs, an evocative soundtrack and his own astute judgment to create a lucid, emotionally affecting portrait not just of one man but of his times. "Going Upriver" is indeed about a long war, one the entire country seems still to be fighting.

Going Upriver: The Long War of John Kerry (92 minutes, at area theaters) is rated PG-13 for disturbing images and verbal descriptions of war.

Filmmaker George Butler focuses on John Kerry's antiwar activism.