With the two most unpopular candidates maybe ever, the 2016 Presidential Election produced a "winner" who got millions of votes less than the other candidate. Joe Biden recently said if he had ran (and gotten the nomination) he would have defeated Donald Trump in the general election. I would say that would most likely be true. Hillary Clinton has been demonized since the 1990's, so it didn't matter what was true, public opinion had turned against her for at least 40 something percent of the country. Joe Biden would have never had the power and energy of the Obama 2008 campaign, but Hillary Clinton was probably the only candidate Trump could have lost to. The irony is that the DNC worked against Bernie Sanders because they thought he wasn't "electable". If it wasn't for Debbie Wasserman Schultz, Bernie Sanders would be president.
Could Joe Biden have won?