A lot of perceptions about the 2020 race have shifted over the last couple weeks, whether the underlying reality has changed is another matter. To me though the biggest story isn’t Biden v Trump or Biden v Bernie or Biden v Warren. All the traction and energy and significance at the moment is the battle between Sanders and Warren, which among its other oddities is only implicitly being joined, at least from the Warren side.
Sanders’ campaign and especially his supporters have taken to attacking Warren over her ties to the Democratic establishment, alleged failures to adequately address health care policy issues and more. The key thing here is that Sanders’ campaign recognizes, accurately, that their real fight is with Warren. Hopefully for Democrats the great majority of every candidates’ supporters will eventually consolidate behind the nominee. But especially reduced to his more ideological supporters (around 15% support as opposed to near 25% support earlier in the spring) Sanders isn’t going to lose those people to Biden. The two are just running totally different kinds of campaigns ideologically, strategically and tonally. But he could lose a large chunk of them to Warren, who is running a distinct but still similar kind of campaign. There’s good evidence he already is. He will also need to reclaim a significant amount of support from Warren’s supporters to get back to something approximating a two person battle between him and Biden.