Still on Sanders...
... one thing I find weird about his supporters is this idea that the Democratic Party has a conspiracy against him and will cheat at every opportunity. While I sympathise with their frustrations, I think that they often have misplaced angst, and should focus on building the candidate rather than tearing down the party.
To clarify the situation, Bernie is not a member of the Democratic Party. He is competing in the Party because the two party system is hard to beat. Democratic socialists have not stood independently for almost a century.
The party is being quite accommodating in this regard. Remember that a party has an identity and sets a strategy for how it wants to contribute to the nation and thus compete in elections. This includes the types of positions it wants to takes. If politicians stand contrary to those positions, then it has a right to focus on the politicians it finds most closely identify with its values.
This is not unique to the Democrats in rallying around Clinton in 2016 and seemingly gravitating towards Biden in 2020. The Republicans desperately tried to prop up Rubio and Bush in 2016. In both those instances, however, a large enough number of supporters was attracted to the fringe candidate. I've just been looking at Trump's primaries. In his case, before they were 2/3 through the primaries, he never got more than 47% of the vote in any state, typically getting 35% and taking some or all delegates. And this forced the Republican hand. Sanders can do more or less the same.
On the Democractic Party, while it has a prerogative to set strategy, that strategy appears to be a conservative one, in more ways than one. They are trying to manage the risk of a) losing swing voters, and b) being labeled socialists. I think those are the wrong focal points. Swing voters are probably being reduced by polarisation (e.g., evangelicals either opting out or leaning right), and Republicans will find a catchy label regardless. What Democrats should rather focus on is just letting a good candidate win and then focus on maximising turnout for them