Joe Biden doing some heavy lifting in this narrative as a VP and one term president. If anything, Joe Biden and Bill Clinton actually prove this point that anyone can become president, both come from very modest means.
The Bushes, however, are a dysfunctional political dynasty stretching back to senator and investment banker Prescott Bush, George HW's father, and Samuel Prescott Bush, a steel executive and industrialist, who was HW's grandfather.
Also, you left out that this is the 3rd election in a row with Trump on the ballot.