Why, in the lexicon of movie issues, does the subject of immigration figure so low? Immigration is something that touches or preoccupies most people in one way or another. There's a rich vein of dramatic potential to be mined - in social dislocation, cultural unfamiliarity and conflict both trivial and violent. When it does form either the backdrop or narrative of a film, you can be sure that the tone throughout, or the ultimate conclusion - even if the film fancies itself as "frank" and "edgy", such as in the case of Oscar-winner Crash - will still be along the lines of teaching the world to sing with one voice. Why can't we just get along, goes the plaintive cry? After all, far more unites than separates us, Coke is the real thing, etc.
There are three reasons, perhaps. First, the struggle of people in a new land is seen as inherently dramatic. There are those all-important obstacles to overcome - more often than not, negative attitudes on the part of the hosts - which, any properly equipped screenwriter will tell you, are essential to your story "arc". Second, it would not occur to most of these writers or directors to approach it any differently, so steeped are they in political orthodoxy. This means that the immigrant will largely be well-meaning and come up against boneheaded racism or exploitation. Stephen Frears's much-praised Dirty Pretty Things - with its cast of blameless illegal workers and music-hall villains from the Home Office, is a perfect example.
But the final reason might have more to do with pure commerce. If you're the head of a studio, you'll think twice about alienating massive sections of your potential audience, especially at a time when more and more movies are being made with 14-year-old Mexican boys in mind. Hispanic immigration into the US is, for better or worse, of momentous import right now, and that means box office. Best perhaps to attempt to be all things to as many people as possible-to make your message, well, universal.