The main issue isn't media. Neurological science has demonstrated that the brain of conservatives and liberals are structurally different. Conservatives see many things as a threat because their main decision making centre is the primitive brain - the amygdala. Liberals make their decisions from the grey matter in the brain, i.e. thought.

The differences can, apparently, be seen by the time someone is 16.

While I agree that there are many news sources that play off people's need to be entertained and titillated, that is not the real problem. The real issue is that liberals and conservatives have fundamentally different vales and ways of looking at things.