Robert F Kennedy announced late in the race that he would run for President. He hadn't wanted to - his brother had been assassinated only five years earlier, when he was less than three years into his first term - but the pressure of public opinion was on him. It was 1968; the war in Vietnam had taken a sharp turn for the worse, there were race riots all over the country, and students were staging sit-ins. Kennedy was considered the only figure who could responsibly argue the anti-war position, and unite not only the conflicting factions of his party but others young and old, black and white, rich and poor. There was an almost inconceivable degree of hope wrapped up in him when, on the night of 5 June, 1968, he took a short cut through the kitchens of the Ambassador Hotel in Los Angeles and was shot, point blank, in the head.

Many people who never lived through those times suspect that reports of the younger Kennedy's charisma have been exaggerated by nostalgia, and by the tragic manner of his death. To counter those suspicions, consider this: every time Bobby Kennedy appeared in public, he lost a piece of himself to the crowd. Sometimes a shoelace, sometimes an entire shoe; at other times fans would grab his tie and yank it from his neck, or claw his cufflinks from his shirt. They would pull at his hair - once he even lost a tooth trying to get back into his car. His friend the political journalist Theodore White, who first associated the Kennedy family with the legend of Camelot, described it as 'a near-sexual orgy of exultation'. Everywhere he went, a sea of hands would stretch out and he would try, like any politician, to shake them. But he was not any politician. On one occasion during his last campaign in California, the labour leader Dolores Huerta welcomed Kennedy past the throngs and looked down at his hands: they were bleeding.

In one of those crowds, in which Kennedy lent new meaning to the phrase 'pressing flesh', was two-year-old Emilio Estevez. He had gone to a political rally with his father, Martin Sheen, and perched on Sheen's shoulders. As Kennedy went by he shook Estevez's tiny hand, and was never forgotten.

Now Estevez, once best known for his roles in the Brat Pack movies St Elmo's Fire and The Breakfast Club, has written and directed Bobby, an impressively kaleidoscopic movie about Kennedy's assassination. The film is not a reconstruction but the recasting of a certain historical moment, the repercussions of which, it is implied, add up to the present one. (Kennedy was murdered by a Palestinian-American named Sirhan Sirhan, who said he had acted in retaliation against Kennedy's views on Israel.)

The camera follows 22 fictional characters - hotel workers, guests, hangers-on - over 16 hours leading up to the shooting, and the film is set entirely in the sprawling Ambassador hotel, which functions as a microcosm of the society to which Kennedy spoke. Ashton Kutcher sells some LSD to a couple of young campaign volunteers, who consider the merits of watching Planet of the Apes while high; Lindsay Lohan marries a boy she knew at school to save him from going to Vietnam; a Mexican bus boy argues with a black chef about 'puttin' the brown man down', waiting for the day when white men will be scared of him, too. (It's worth noting that Estevez, unlike his father or his brother, Charlie Sheen, kept the family's Hispanic name.) Meanwhile, on a TV in someone's hotel room, Bobby Kennedy speaks to a group of schoolchildren. 'They are not registered to vote,' the announcer says, 'but in 10 years' time they will inherit the problems we don't solve today.'...