If you calculate the difference between percent rating the parties at 100 and 0, you get:
So the kind of partisan polarization that has grown isn't a matter of enthusiastic support for one's own party, but dislike or fear of the other party.
1. For this post and the previous post, I used the online data analysis system SDA, which lets anyone do basic analysis of the GSS and ANES. I have a link to it in the data sources section.
2. In 2012, Shanto Iyengar, Gaurav Sood, Yphtach Lelkes published an article entitled "Affect, Not Ideology: A Social Identity Perspective on Polarization," which argued that contemporary partisan polarization was based primarily on feelings of dislike rather than ideology. I thought it was pretty convincing when I first read it and this analysis has made me more convinced.