Morgan ‘Super Size Me’ Spurlock is the kind of documentary maker you either love, or you hate. Those in the first camp say he’s inventive, approachable and witty, while those in the second say he’s low-brow, biased and patronising. Well, those in the second camp might want to avoid this second episode of the second series of 30 Days, currently being shown on More4. Or perhaps you should give him another go, cos he’s great.

This series takes the ‘do something potentially dangerous for a month’ idea from his McDonald’s-bashing feature film, but tackles a different subject each week – though, perhaps wisely, Spurlock has decided not to take on every challenge himself.

While the series started with Spurlock spending a month in prison, the main point of the series is to get ordinary people to put themselves in an unfamiliar situation – one that’s often incongruous with their own beliefs or ideas – and it’s usually these episodes which are the most interesting, revealing and very often ulitmately life-affirming.

This week, Frank George, who’s described as a ‘gun-toting, border-patrolling anti-immigration vigilante’ (he does this work completely voluntarily, along with an astonishing 7000 others) spends a month with a family of illegal immigrants from Mexico. It’d be easy for this show to turn into a weekly slap on the wrists for ‘unenlightened’ Middle America, but Spurlock’s too canny and sensitive a film-maker for that ever to be the case.