Using data from a variety of sources, we demonstrate that both Republicans and Democrats increasingly dislike, even loathe, their opponents.

We also find that partisan affect is inconsistently (and perhaps artifactually) founded in policy attitudes. The more plausible account lies in the nature of political campaigns; exposure to messages attacking the out-group reinforces partisans’ biased views of their opponents.

This makes a bunch of sense when you think about it. What is the primary form of communication to low-information voters? Political ads. What do they do? Intensify contempt for various candidates along stereotypical partisan lines. Rinse and repeat ad nauseam, and cut yourself off from anyone with a different viewpoint, and you have our gridlocked society. And all the Supreme Court seems to do is usher in yet more money to finance yet more of this poison; and all the media seems able to do is reach for ratings by exploiting these emotions.