I just find it odd. The Dems, in their infinite wisdom, seem to be more interested in purging their own in the interest of purity, go after each other for whatever, etc. The problem is that this kind of behavior is not smart and can lose them 2020. They seem to forget who the enemy actually is. I would love to see one of the candidates, besides Biden, to after Trump and the Republicans instead of each other, with some regularity. I suspect they do more of that when actually speaking but, on tv, not so much.
The problem with all of this is that nobody really knows where the Democrats stand on all sorts of things. What they do know is that they are socialists, love to fight with one another, make promises they cannot possibly keep (Warren does this one in Spades, ie free higher education, free baby sitting (lots of 'free' stuff), paid leave when baby comes - both parents, 30 trillion dollar healthcare, etc ), and make absolutely sure that nobody has a clue as to where they really stand.
Actually Warren is, I think, an expert on things economic. One would think that the simple fact she will inherit a Republican national debt of over 23 TRILLION dollars one would think that she might, occasionally, point out the REPUBLICAN National Debt, and what it means (which is not good). For instance, when Dems talk about the debt they should say; "Republican National Debt". When they talk about healthcare they should say "For-Profit Healthcare", etc. The Republicans would not make these kinds of mistakes. The Republicans are wide open to this kind of thing but the Dems, again in their infinite wisdom, just cannot seem to bring themselves to behave in such a bad way.
However, all that being said, between Bernie and Warren they have pretty much turned off the entire middle ground and a lot of that group tends towards Democrats, as long as they are not socialists or giving away the store (which both do). I am not convinced that they can actually beat Trump unless the economy tanks (there are a number of polls that agree). I would feel a lot better about those two if they actually took time out from promising everything to going after Trump and the Republicans.
Then there is Biden. I have listened to him speak. I am not convinced he knows what day it is. There are reports they have him pretty much in a bubble and it shows. Bernie is too old and so is Biden.