Childhood socioeconomic status (SES) is associated with cognitive achievement throughout life.
First of all, even if you look only at the direct impact of rising inequality on middle-class Americans, it is indeed a very big deal. Beyond that, inequality probably played an important role in creating our economic mess, and has played a crucial role in our failure to clean it up.
People always say education can be the great equalizer, then they turn around and siphon out resources and kneecap the profession of teaching. You know why they say poverty is nothing but an excuse? It is because the money it would cost to address it would go into our schools and not into their bank accounts.