Its interesting that you mention Corbyn when if you look into the data Starmer got much lower voters than he did but the UK system works in strange ways. I should mention I was one of those that refused to vote for Corbyn on the allegations of anti-semitism but those later turned out to be untrue.

One thing I have to ask about the democrats and a fear of Corbynism is shutting down primaries really and effective way to prevent one? Voters aren't stupid and the not being able to freely choose their candidate since Obama isn't going to help.