currently doing some reading for my brand strategy class and something that struck me is that people generally respond more strongly to the negative than they do the positive. It takes something like 5 positive interactions with someone to undo an initial negative interaction.
The same goes for all this politics. If you lie about your opponent (for example, the libertarian candidate for governor in nys was called a sexual offender - when, in fact, he is not) or construe things that they've done in a very negative light - people are much more likely to let the negative things inform their opinion of the candidate rather than anything positive that is presented in a different ad or from a non-partisan news source.
These kinds of things lead me to a general apathy about the political process. Not apathy in that "i don't care"...because i genuinely do - but apathy in the "i don't want to care" because people are so messed up and any hope for people to do the right thing is a false hope - and i don't need the extra drama.