Well, I don’t think he was “screwed” by Clinton. I think he lost by a fairly decent amount because voters chose Clinton, and progressives have made way too much out of the DNC rather than look at Sanders’s own mistakes, which he’s clearly trying to fix this go-around.
I do blame some progressives for pushing arguments that were spurious and dumb during the election and only justified a Trump win. Arguments like considering the Supreme Court was “pushing fear voting” were stupid, and they will look stupider as time moves forward. I thought that at the time, said so here, and continue to believe it.
And, save your non-voters argument for somebody else. The idea that non-voters are all secret progressives is nonsense. Every election there are lots of people that don’t vote for a variety of reasons. In 2016, the atypical voters that did come out in the states that tipped Trump were white, rural, and responsive to racial appeals. “Economic anxiety” is just a nice gloss we in the progressive sphere like to spread around amongst ourselves, but it can play out as fear “illegals” and minorities are taking tax money for “free” stuff. Trump is doing that now, right?