Super-ignorance is one of several categories of information dysfunction that are helping to destroy America. This is a new condition that is greatly facilitated by the morally neutral tools of the Internet.
The basic idea is that people tend to believe what they want to believe, but the Internet makes it MUCH easier to do so. Everyone has a limited amount of time, but with the Internet search engines it is easy to saturate that time with so-called evidence of any crazy thing and thus completely avoid the much larger rational parts of the universe. Some years ago I anticipated this problem as 'pandering by the search engines', though now it is actively marketed as 'personalization and customization of the search results'. Basically the same thing, but I regard pandering as the dark side of the coin.
As it's working in America, this has become a key part of the political dysfunction that led to the recent manufactured crisis over the federal debt limit. It doesn't matter whether you favor democratic or republican forms of government, one essential for all such non-dictatorial forms of government is rational discussion of the problems of the real world before considering rational solutions. That is obviously NOT what happened over the last few months. It isn't a house divided against itself, but more like a house where certain rooms are in alternative universes, and never the twain shall meet.
At least two other information dysfunctions are of concern, both augmented by the Internet. One is just awareness by the impoverished of the way rich Americans live, causing them to see us as living high on the hog as a result of grinding their faces in the mud. The other is the malicious identification of borderline crazies to be pushed over the edge. Maybe the recent Norwegian madman or some of the American shooters were pushed?