The Competition for Attention

 Ezra Klein in his "Why We're Polarized" points out there's been a big increase in the competition for attention (my term). In the 1970's we had 3 TV networks plus PBS, a newspaper and a handful of magazines which provided political information.  And access to material published in the past was limited.

Now of course we have more networks, more channels, more social networks and almost everything written remains available.  Perhaps even more significant, the same explosion of channels has happened for ally and all interests one can imagine.  Consider the availability of porn, with every peculiar interest/fetish being served up in a way unimaginable back in the 1970's.  Consider the handcrafts, all the networks and organizations set up to serve knitters, weavers, etc. etc.  

Everything I've mentioned is competing for attention.  People don't have unlimited time and money to devote to everything which might be interesting, so they have to specialize.  In the case of political interests, that tends to mean more controversy--controversy sells.