Sanders risks looking like a sore loser with this whole superdelegate conversion thing.  And whining about the party registration rules.  They have existed for a long time and while it's great that more people are paying attention to the nitty gritty of politics, trying to change the rules during the primaries is waste of time and distraction from the issues such as women rights.  Those who earn superdelgate status have been going to meetings weekly and monthly for years, not just in the election season and election year.  Concerned, involved citizens deserve this position, and they are there to do what's best for the party and avoid demagogues. Sanders is a recent convert as a Democrat, he's not giving the party any money (unlike Clinton) and should be focusing his supporters' attention on taking back the Senate rather than bashing fellow Democrats. He's not really a progressive since he won't go up against the big gun manufacturers and the NRA – a huge disconnect.