RE: it taking Hervis Rogers 7 hours to get to vote, it's so fucked up that our citizens have to go through that shit just to exercise their constitutional right.
You make a good point. Considering how predominantly white the Warren bloc has been, her supporters (or at least a portion of them) moving to Sanders doesn't help him much in that department.
Your sense of this is similar to mine - a little more than half of her support would probably flop to Sanders, with a smaller but still relevant chunk probably going for Biden.
But at this point, forget her effect on Sanders - her staying in doesn't help her either. She hasn't won a single state, or even placed above third, including an embarrassing loss in her home state. She has nothing to gain by limping to the convention with a few dozen delegates.
Sanders has made inroads with the black community since 2016 - recently polling ahead of Biden among African American voters nationally - but he still has a lot of work to do on that front and I'm not surprised that Biden retained a lot of his strength with them. The man's tenure as Vice President to the nation's first black President has played a much bigger role in his public image over the past decade than his (generally awful) legislative record in the preceding decades. The other big story here, in my opinion, is the media's utter failure in covering Biden and carrying water for his campaign's ludicrous "I'm the safest and most electable" nonsense. Exit polls show electability was a huge issue for voters, so it would seem that opposing campaigns and the media were successful in painting Sanders campaign as risky and uncertain when it comes to beating Trump. Which is sad because I have little to no expectation that Biden can win.
Given how soft the media has been on Biden (that Mandela lie was barely a blip on the mainstream news) and the degree to which his campaign has tried to pass itself off as something it isn't, Sanders' best option at this point is broadcasting, as loudly and clearly as possible through any means available, the massive gulf between Biden's friendly public image and his awful record / plans for the presidency. It will be an uphill battle, but having only one target has potential to give the campaign focus. It's not over and I'm not giving up.
While I understand the rage and frustration behind this corner of Sanders' supporters, I will be the first to admit that they are often too aggressive and scathing for their own good. But if snake emojis on Twitter influence someone's choice of candidate more than, say, trying to stop people from dying because they can't afford healthcare, they are as privileged as the Bernie dead-enders who sat out the general in 2016.