Idiocracy is a decent movie. It's somewhat entertaining, although not enough to warrant a second viewing from me. It is not, however, interesting, or deep, because the basic premise - if one were to argue that Idiocracy were arguing something - is just plain wrong. Society is not getting dumber. Just the opposite, in fact. People are smarter today than ever before in human history, and I predict this statement will remain true for as long as 'intelligence' is a measurable trait.
There are a number of reasons for this. The first I want to bring up is that people today are healthier than ever before in human history, in large part because of better nutrition. Despite the popular conception that our diets are somehow worse today than in the past, the simple act of taking a daily multivitamin wipes out a wide range of deficiencies common in premodern times. These deficiencies were essentially universal, although they varied from one region to the next. Fatal deficiencies were, of course, fatal, but there are many more that the body can work around - but result in stunted physical and brain development. This used to affect vast swaths of the population. Nowadays, well-nourished health is the norm, not the exception, with the expected effects on intelligence (and overall body size, life expectancy, etc).
The link between nutrition and intelligence is well-documented, even if all the mechanisms are not well-understood.
The second reason I want to point out is that educational attainment is higher today than ever before in human history. Again, I expect this to remain true for as long as education exists.
Lastly, and most importantly, I have the data on my side.
So, while I have no doubt that everyone enjoys dropping the "I feel like I'm in Idiocracy" line, you don't actually feel like that. You might, however, were you placed in pretty much any premodern society - you'd be surrounded by malnourished, mentally underdeveloped, illiterate people. Let's not pretend that individuals in the past were any more intelligent than those in the present - because they were not. Your fellow human beings are the smartest ever to live, and that's worth remembering as you go about your life. For myself, at least, this demands a certain respect for and from us. And, I insist, our democracy.