Many things are well known about Ralph Nader, and the film honors them appropriately: his 1963 Corvair crusade against General Motors, which put him on the map by sending detectives after him and getting caught at it; his ardent advocacy of such consumer causes as seat belts, air bags, clean air and pure food. (He once called hot dogs "missiles of death.") "An Unreasonable Man" also contains its share of oddments and revelations. A glimpse of his office through a barely open door suggests the document-choked lair of a certified pack rat. During an exquisitely ill-at-ease appearance on Saturday Night Live, he wore an airbag that was supposed to deploy, but didn't. George McGovern wanted to consider him as a running mate in 1972, but Mr. Nader's influence declined precipitously during the Reagan years, when support from the Democrats waned as well, and that influence didn't begin to rebound until he reinvented himself as an ever more outspoken outsider.
"An Unreasonable Man" doesn't polish its subject's reputation -- his detractors call him deluded, or worse -- or soften his hard edges: He calls the nation's political system "one corporate party with two heads." But the film contends admiringly, and convincingly, that Ralph Nader's authentic sense of outrage is the reason he persists when he can't prevail.