Have we gotten so used to the idea that the USA is politically polarized--the red and the blue--that we, and certainly Democrats, have lost sight of the issue of increasing income inequality and its causes?
I continue to emphasize that I believe the central political issue of our time is exactly this -- that the gap between rich and not rich is getting unacceptably large.
A recent book called Polarized America, by Nolan McCarty, Keith Poole, and Howard Rosenthal, examines the relationships of polarization, wealth disparity, immigration, and other forces, characterizing it as a dance of give and take and back and forth causality.