Robert Drew's documentaries captured the Kennedy mystique—and changed presidential politics forever.

Is there a less spontaneous creature than the contemporary politician? Surrounded by banks of TV cameras, candidates have been trained to stay on script, follow stage directions, and play it safe, lest YouTube claim another scalp. The race itself may hold surprises, but presidential campaigns stick to the photo-op playbook—glad-handing in the New Hampshire snow, visits to Midwestern diners, stopovers at Rust Belt bars. The campaign has become not so much a breaking story captured by cameras as a choreographed production put on for their benefit.

It was not always thus. In 1960, journalist Robert Drew came up with the idea of following Massachusetts Sen. John F. Kennedy with a movie camera during his run against Minnesota Sen. Hubert Humphrey in the Wisconsin Democratic primary. But it wasn't the story so much as the way Drew got it that made the project memorable. Drew and crew were equipped with newfangled movie cameras that gave them unprecedented mobility. The result, Primary, was the first of its kind: a freewheeling, fly-on-the-wall documentary with no interviews, no music, no correspondent, and little exposition.

Stacked up against today's documentaries, which tend toward overweening subjectivity and strident polemics, Drew's movies seem like relics. Here, it seems, was the first gaze—the audience granted an intimate glimpse of their leaders, the subjects not yet trained to play to the cameras. Ironically, Drew's innovations would end up killing the very spontaneity he captured. The ubiquity of portable cameras, whose development Drew helped speed along, would eventually usher in the era of media-trained politicians.

Considering his role as one of the godfathers of cinéma vérité, Robert Drew is a curiously obscure figure. Indeed, some cameramen who worked with him, including D.A. Pennebaker (Don't Look Back, The War Room) and Albert Maysles (Gimme Shelter), have achieved greater fame. A newly released box set of Drew's Kennedy films, Primary and Crisis, offers a vivid reminder of his enduring influence on both journalism and filmmaking—and a poignant testament to the Kennedy mystique.

Click here for a video slide show on Robert Drew's Kennedy films.