I can see the case that a centrist moderate DEM could/should win.
Trump is so extreme and offensive that it should just take a competent centrist to sweep up the middle and walk away with it.
But Biden and Mayor Pete seem like the weakest options.
Biden is exactly the type of old school hack the DEMs tend to run. A Mondale. His candidacy seems based solely on name recognition, being a Friend of Obama, and being affable. The gay military mayor is certainly an interesting story, but it's like Ukraine voting in a TV star who played a regular guy becoming elected president.
Uncle Joe and Mayor Pete seem like the type Trump would love to go against and steamroll. I suppose this is exactly why Bloomberg jumped in. He has name recognition and money, even if nobody outside NYC really knows who he is or why they've heard of him. But it's easy to see a potential open path in the middle. Just need Biden to slip.
It's unfortunate that Warren and Sanders are splitting the progressive vote. If just one of them were in, they could wrap up support and money and possibly have a significant lead.