Paths to Victory
Here are the possibilities for how Bernie could win:
1) He wins the majority of pledged delegates and thereby persuades superdelegates to vote for him.
Credibility: It would require him winning 60% of the remaining pledged delegates, which is feasible but a little unlikely.
2) He does not win the majority of pledged delegates but persuades superdelegates to vote for him anyway.
Credibility: There are several possible reasons this could happen: superdelegates may take into account the many signs of voter disenfranchisement and decide that the vote has not accurately picked up the will of the people, in which case the superdelegate must choose on other grounds. Polls, favorability ratings, and wide support from independents favor Bernie. Also: I have CNN interview credible people (i.e. Attorney Generals, former FBI personnel, etc.) who say in no uncertain terms that Hillary will be indicted. Reading what has been said, it's pretty bad. The FBI cannot allow people to believed that Clinton can outsmart them (they have a reputation to guard), so she will be indicted if she has done anything wrong, and I for one suspect that she is hiding something. An indictment or even the possibility of one may sway the superdelegates.
3) Bernie decides to run independent.
Credibility: This is only feasible in a four-candidate race. In other words: repubs end up with a split ticket between (say) Cruz and Trump. Then Bernie would be a fool not to run. However, as Trump will probably win the repub. nomination (in this guy's opinion, anyway) and since Trump's threatened third-party candidacy may be nothing beyond a threat, this is the least likely option so far...
Those are the paths to Victory. The 'Path to Failure' would involve Clinton successfully shaking off the FBI probe and also, at bare minimum, securing/keeping the superdelegates, a move that may be a bit harder than hrc and her fans assume.
I think the odds are in our favor. Feel the Bern.