It's one of the paradoxes of human existence; things that don't really exist can have an incredible amount of meaning. Nature doesn't make national borders; people do. In Crossing Arizona, director Joseph Mathew looks at illegal immigration to America from Mexico by looking at the people and politics of one region, and the end result is a documentary that casts more light than heat on both sides of the issue, even if you can't help but wish the film had actually come up to a slightly more invigorating boil.

Mathew's careful to talk to a broad spectrum of people – policymakers and migrant workers, coroners and community activists, the border cops trying to stop illegal immigration and the 'coyotes' who lead people from Mexico to America in exchange for  money. Mathew's also not shy about exploring the cold, hard economic facts of illegal immigration. Every time you go to the grocery store for produce, a shadow-shrouded Arizona farmer explains, you're benefiting from illegal immigration. A chili-picking migrant worker explains his view of the same phenomenon: "Gringos don't want to work here. Only Mexicans work here. Gringo's don't want to work. Only in the office." He then mimes typing and laughs ruefully.

So we see the efforts of groups like No More Deaths, which places water in the desert for illegal immigrants to use so they can survive; we also see the efforts of The Minuteman Project, which creates citizen patrols to watch the border and do the job they feel the Federal Government is shirking. (The sequence built around The Minuteman Project – as a piece of regional political activism becomes a national media circus – is easily the most satisfying part of the film; you wish the rest of Crossing Arizona had the same snap.)

Crossing Arizona moves sure-footedly from air-conditioned TV studios where pundits spout blather (Bill O'Reilly speaks his praise for how well the Red Chinese have prevented illegal immigration from North Korea, and points to them as a model for the US) to the heat and dust of the desert Arizona and Sonora share, where corpses grow stiff and taut in the sun and heat that killed them. Crossing Arizona shows the audiences several corpses, and it seems gratuitous only until you recognize that these few dead are representing hundreds, thousands more. Crossing Arizona may not have the muckraking whip-crack energy of more attention-getting documentaries, but it's got a careful, graceful intelligence that finds the individual people and the big picture in a complex, real issue of concern.

Others on Crossing Arizona: Writing at Variety, Dennis Harvey described the film as "a potent plea" for a change to federal immigration policy.