Nothing in the presidential primary race was a surprise tonight, and it looks like Biden is, for all intents and purposes, the "presumptive" Democratic nominee. We now enter a weird period where there won't be any contests until April 4, so even if Sanders does choose to hang around, the combination of Biden's sizable advantage and, perhaps more importantly, the laser-like focus on the public health crisis will move the primary race to the background.
I doubt there will be any more debates, for example, given these developments. All of this could make it more difficult for Sanders to break through if his plan is to hang around and influence the party by pushing Biden to the left. I wonder if that will end up being part of his calculation moving forward. We'll see.