Here’s a short news clip of Robert F Kennedy advocating legislation to make it harder for young people and the mentally unwell to get hold of guns. It was a speech he made over half a century ago. And it was an especially poignant call given what had happened in Dallas to his brother, and what would happen to him, infamously, at the Ambassador Hotel in Los Angeles on 5 June 1968.

This particular clip comes halfway through the second episode of four. And still he hasn’t started the race for the White House. The title of Dawn Porter’s series is misleading. That campaign, and its tragic end, is taken care of in episode three. Episode one is more about JFK and that tragic end, two is about Bobby’s civil rights involvement, and the final episode is about justice, legacy and conspiracy. It’s all about the context too, what was happening outside the Kennedy cult, in the US and in the world – Martin Luther King, Watergate, Cuba, Vietnam and the restive 60s. So it pretty much covers Bobby Kennedy’s entire political journey, what he stood for and why, and what he left behind.

As an account – and as a journalistic document – it’s impossible to fault. Meticulous, exhaustive and perceptive; Porter has sifted through yonks of archive: she takes a snip from the news here, one from a home movie there, others from rallies, speeches, holidays, and there’s room for the dog. (I’d like to have seen more of Freckles – who did, after all, become a politicised pooch.)

There are also talking heads – aides, advisors, representatives, the civil-rights hero John Lewis and Harry Belafonte for stardust. And it’s strung together into something cohesive, meaningful, and balanced – it doesn’t ignore RFK’s aggression, the McCarthy association or the wiretapping of Martin Luther King. This is no whitewash.

Nor is it just the gun control element that reverberates now. Danger abroad, poverty at home, civil unrest, disaffected youth, electoral interference (perhaps). Different times, same issues. And above it all hang big what-if questions: what if he hadn’t been killed that night, by Sirhan Sirhan (perhaps)? What if his brother hadn’t been killed? Would we be somewhere else today?

But the show really only comes alive in its final episode. Until then it’s accomplished but a little dry. Then, without going into detail, it becomes more than a classy cuts job. It has life breathed into it, becomes more investigative. But also more personal, more touching.