I'm getting increasingly pessimistic about Democrats' 2020 chances, and I'm not someone who views Trump as 10-feet tall. The guy lost the popular vote and got all the breaks last time around. The Comey letter and the electoral college saved him and he's never been popular since. A good candidate could easily beat him. But unless someone breaks out, the Democratic race is down to two not great candidates. Biden is old, undisciplined and not quick on his feet and gaffe-prone. His message is cultural and not economic in nature, it's rooted in "remember a better time when..." He suffers from what doomed Ted Kennedy and later Hillary Clinton - "Why do you want to be President?" People want an economic message that resonates and Biden doesn't have one.
Warren has an economic message, but it's readily seen as a radical one to swing voters. And that's a perception she almost wants, she's a true believer and thinks her policies are right and will carry the day. She's a caricature of the ivory-tower, east coast elite. Yeah, she has a middle-class backstory filled with struggle, but on a cultural level people don't believe that's who she is now. She's the Harvard professor turned Massachusetts Senator, it's hard to be more reflexively left-identifying than that.
I think Biden stands the better chance. He has a guttural, cultural connection to enough rust belt and midwestern voters. There's still persuadables there and a lot of them think he's with them. He can probably carry the day although I'll be constantly on edge because his raw political abilities are low. He's a great Senatorial backslapper and a backroom deal-maker, but his campaign talents are low.