The premise of Idiocracy is a classist one: the people with lower intelligences (laying aside the multiple critiques that could be levelled at a ‘g-factor‘ theory of unified intelligence) reproduce more frequently, and come to dominate the population.
For reasons that are complicated and irrelevant, an average person ends up there, and by virtue of being average in a land full of people with low-IQs, is instantly above average. This is the basic premise of the movie.
But implicit in the portrayal of Idiocracy, although not explicitly spelt out, is that corporatization consumes much of modern society, leaving little in the public space that doesn’t have a logo stamped on it. It seems that society breaks down, and things fall apart – hospitals are filthy pits of disease, and rubbish litters the streets.
It’s a fascinating premise, with a lot of potential. Sadly, Idiocracy doesn’t live up to that potential. The plot’s basic, the ideas are even simpler, and threaded throughout are boringly stupid assumptions about gender. This isn’t one I’d recommend to others.