ENFANT TERRIBLE
An incorrigible CHILD as one whose behavior is embarrassing. An outrageously outspoken or bold person who says and does indiscreet or irresponsible things. A person whose work, thought or lifestyle is so unconventional or avant garde as to appear revolutionary or shocking.
If Joe Biden somehow gets nominated, I would agree with your prediction.
If the nominee is Sanders or Warren, I think it might produce a turnout surge similar to the 2018 election (I had to wait in line 1.5 hours to vote) which would produce a 2016-like result in the popular vote.
Whether that's enough to overcome the structural disadvantage the Electoral College imposes on the Democratic Party, I don't know.