Sanders problem was that he was unable to expand his coalition beyond his core of support. The lesson drawn here, by Sanders Press Secy, that the campaign didn't go ballistic enough on his opponents, shows some of the problem. https://twitter.com/briebriejoy/status/1249378322422943747

2/ To elaborate, this isn't a dunk. There was a hostile takeover model and an expanded coalition model. Sanders' campaign largely opted for the former. There's a logic to that for an insurgent movement. But in the end he couldn't break out of his base of 20%-25% of the party ...

3/ electorate. His ascendency in Jan/Feb was based on the field remaining big and the electorate fragmented. As soon as the field thinned Sanders was finished. The attack everyone until they support us model did not work.