For one largely forgotten week in 1972, John Lennon and Yoko Ono transformed the most popular show on daytime television into a forum for ideas that its unsuspecting audience rarely encountered. Joining as the co-hosts of “The Mike Douglas Show,” they repurposed entertainment as a Trojan horse for activist agendas (antiwargppbet, pro-civil rights), briefly bridging the yawning chasm between mainstream America and a counterculture that the Nixon Administration was actively engaged in repressing.

That chasm is the real story of “Daytime Revolution,” one that Erik Nelson’s charmingly relaxed, almost cozy chronicle of that week strains to elucidate. Given the flammable reputations of some of the show’s guests, like Jerry Rubin and Bobby Seale, the most shocking takeaway from the movie is how tame it feels. The mood is overwhelmingly congenial and playful, with Ono’s dippier contributions drawing titters from the audience and occasional bafflement from her perpetually gum-chewing husband.

Everyone, in fact — even a subdued, impossibly handsome Ralph Nader — seems on their best behavior, if slightly on edge, as though expecting an F.B.I. raid at any second. (They probably knew that Lennon was already on Nixon’s naughty list.) Musical segments featuring a vivacious Chuck Berry and the magnificent Broadway performer Vivian Reed keep things grooving and lighten the earnestness, as do engaging present-day interviews with Reed and other surviving guests.

But for “Daytime Revolution” to live up to its name and become more than a curious cultural artifact would require a richer historical context, an explanation of why these people mattered and why their views were so feared by the White House.

“I did not want to make a film about the thing — I wanted the film to be the thing,” Nelson states in the press notes. As a result, the movie’s quiet star is Douglas himself. Whether gently asking a tense Rubin about his upbringing, or helping Ono with her “box of smiles,” Douglas’s kindness and intellectual curiosity are more compelling than any political argument.

Daytime RevolutionNot rated. Running time: 1 hour 48 minutes. In theaters.gppbet

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