For Bernie to make his legacy historic he must break from the Democrats. Trump and the GOP are the low hanging fruit- sure they are evil, its obvious and they will screw their own constituency. Sad but IMHO a necessary step.
The Democrats are more insidious. Glen Ford from Black Agenda Report referred to Obama (when compared to Bush) as the more effective evil.
Bernie has to embrace a larger picture here. Not specific legislation that he might get some crumb of a compromise on.
He identified the overarching corruption of the American political system. His speeches about how the Democrats must now do this or that only diminish him.
He must stand up and say Trump is scum - absolutely - but he must run with the Wikilweaks (and not fall prey to the Russiaphobia - inspired by the Nuland/Kagan war family) and talk about how he was robbed of a place in the election. The DNC's fixing of the primary is real, - the Russia fix is speculative.
https://consortiumnews.com/2017/03/15/the-kagans-are-back-wars-to-follow/ (this is what the Democrats stand for - war and more war)
Now is the time for Bernie to take leadership of the Greens (rename it - the "gainful employment party - or Justice" ) - get into every state and prepare for the mid terms. He is the most respected politician in the USA. And focus on the economy, education and healthcare and little else. Reeling in Wall Street and extricating from needless wars (reach out across the floor to Paul on this issue) are tied to those main issues.
A healthy economy with gainful and fruitful employment allows all members of society a place at the table (What the NY Times (that dirty rag) called a "crisis in democracy" in the 70's.
He will make a dent in the midterms - he diminishes himself and insults the intelligence of his supporters to suggest they support Democrats.
Fighting for the downtrodden is by giving them employment and allowing them to fight for themselves. Universal health (body), education (mind) - gives everyone a chance in the free market. Stress free enterprise - not capitalism/corporatism. They are not the same thing. Free enterprise is the American Dream - corporatism is the destroyer of the American Dream. He needs to educate people across the board that so-called socialism allows for true free enterprise when everyone is free of basic needs (Health- education).
When factoring in US military work - the US is 33% nanny state. Sweden is 2%. The view of what is socialist is skewed.
Bernie - do not go after Trump just to bring us back to Clinton/Dems and Kagan/Nuland wars.
He has a chance to be a major American figure - but he has to break rank.