If I were a Democratic strategist, I would hit hard on one of the most moving points in Biden's speech -- a lesson and value inculcated by his mother -- she was fantastic by the way, just in her expressions, -- one of the most important American values... that we are all equal,  that no one is our superior, nor our inferior.
American values are democratic values...and these are values we can cherish, we can be proud of, and that the Republicans have betrayed. 
Overthrowing centuries of feudalism and aristocratic prerogative, the founders really did believe that this nation was a fantastic experiment in egalitarianism.
So, I would hit hard on the rise of a new oligarchy and economic inequality that Republican policies have enabled.
I would also so that every immigrant to this country cherishes these values, and yearns for the egalitarian promise of this country.
We were just in Europe to see my husband's family and my own parents are immigrants. Joe Biden's mother's ideas of equality would be extremely challenging to our ancestors...Egalitarianism represents a powerful new political order. The ideal of equality is essential to our national political identity -- and its realization is incomplete, even deeply flawed, but that means we have to work harder in its name -- Americans that can hail to the Mayflower and the newly sworn in immigrant do have something in common...the aspiration to greater liberty accompanied by the commitment to greater social equality at every level of the body politic.
Like a laser