the difference is when Trump was getting scolded by the GOP establishment for shytting on Romney, McCain and other Repubs, he had Breitbart and other big conservative media people on his side. We don't have anything to level of that + Trump being a celebrity helped. The GOP voters hate their party so any establishment coalescing wouldn't have worked.
Trump used his movement to wield power and consolidate establishment support after he won states. After every state he won, he called up the Governors, Senators and house members... and threatened them with his people, endorse or else... Bernie should have tried that after Nevada tbh
If Bernie can’t win after all these years of building a movement, then I don't know who can tbh. The institutional obstacles are just too big. The left should focus on taking over state parties and destroying the liberal media. Plus we had to deal with competing with Warren during the plan war for the very liberal bloc and it took a full year to get some of them back. Most of our left media failed this primary honestly lol