Joe Biden is the favorite candidate of African-Americans. Bernie Sanders is the favorite candidate of the young snowflakes. Pete Buttigieg is the favorite candidate of white upper middle class adults. Only one of these can be the nominee, assuming Bloomberg doesn’t “buy” the nomination.
The question for Democrats is whether any of these can motivate all of the party faithful to turn out and vote for him. Each has weaknesses.
Biden isn’t much of a campaigner, and sometimes seems to be losing it. Sanders turns off people who understand that socialism is a recipe for economic disaster a la Venezuela. Buttigieg turns off the young and blacks, not certain why. As mayor Bloomberg favored the stop and frisk policing blacks hate, plus short candidates like him almost always lose.
A betting person would conclude that, ceteris paribus, Donald J. Trump is likely to win.