Bernie is both right and wrong. Is Biden corrupt - or rather more corrupt than most other politicians? I think Biden is a normally corrupt politician and I don't blame Bernie for playing politics to try to keep a coalition together to beat Trump. But the left and Fox commentators (of course) criticize Bernie for saying he's sorry for the Teachout article. But she makes some very important points.
I watched some comments on Tucker Carlson and others on Fox who wanted Bernie to slam Warren and - of course they would -- but some of what they said had some truth - Bernie does not have killer instinct - they felt if he went all Trump he could be a massive force. Remember this is how Trump took over the Republican Party. Bernie will not be able to do the same to the Dem party because this is not Bernie personality. If it was Hillary would never have taken that recent hit at Bernie. But I prefer Bernie as he is and not as a Trump clone.
But we do get that there are many people who do not love the Dem party and lean toward Bernie the more the attacks come. (I saw some doozies on The View the other day.)
Here is some commentary on the issue.