1) It is not a question of whether the Democratic Party establishment will attempt to smear and destroy the Sanders insurgency if it manages to get more of a footing but how they do so.
(This has, of course, already begun, see, e.g. here and here.)
3) Related to 2), according to two reputable press accounts, the NY State Democratic Party will not allow Sanders to compete in their primary. If that is so, Sanders won’t be able to acquire enough delegates for a win, and the campaign is effectively already over. (Does anyone have any information on this point? If so, please post it in comments.)
4) Once the campaign is over-either sooner or later-the question becomes what it always has been: In which direction will Sanders supporters (i.e. the principled left in the DP and outside) channel their activism? Will they be able to form a Syriza style insurgency. Again, history does not make one optimistic, but this time could be different.
Who knows? Of course, it’s the only question which matters.