The system is definitely weighted heavily in her favor, but that still has been somewhat overstated in regards to impact prior to the use of super-delegates; Clinton is simply more popular than Sanders, and given the primaries have actually favored Sanders as compared to mail-ins and polling (which are traditionally more accurate for the eventual elections), her ~3 million vote lead and lead in the elected delegates count is fairly telling despite the support she receives from the party and her many endorsements.

Sanders has benefited enormously from probably the weakest field we've seen from the Democrats since the days of Dukakis to contend with (if there was even one conventional democrat in this race not named Hillary they'd likely be running away with this) as well as being (along with Trump) the first social media candidates (Trump was likewise hated by both the news and his party and yet pulled away), but even then he still has a ceiling due to how far from the center he openly admits he is. On that front, his integrity (as in that thing Trump chucked out the window) has doomed him as most of the country is still uncomfortable with politics that stray that far too the left.

Of course, if he somehow did win the nomination, this may be the first time someone of his kind would actually have a shot of winning as the Republicans are ALSO in the worst shape they've been since Trump's former Reform Party blew any chance the Republicans as Ross Perot ate up their votes. That may weigh on the minds of the superdelegates if a true shitstorm hits Clinton in the coming days, but as you say that's about the only chance left for him at this point.

In regards to Nate Silver and his team, I still post their articles as they are exceedingly insightful and interesting reads, but it's funny to note that for the first time they (and especially Nate himself) were horribly wrong this election cycle. I recall Nate confidently giving Trump a 2% chance about a year ago, and Bernie has shot well past any projections they had. As I stated earlier, the importance of endorsements and mainstream media have diminished due to the rise of social media, and that seems to have benefited figures as vastly different as Sanders and Trump; people are actively rejecting what they believe to be mainstream in numbers never seen before, and so their predictive models and polling failed them.

Allow me to contradict myself in regards to endorsements as I close though lol... One interesting factor that could essentially be the kingmaker is the Obama endorsement which he still holds. If Clinton continues to look bad and Sanders exceeds expectations today, his endorsement could sway superdelegates. It's almost impossible that he'd stab the Clintons in the back like that, though, and if he endorsed Hillary it'd end there and then.

http://www.cnn.com/2016/06/06/politics/hillary-clinton-nomination-2016/index.html

Do you even read what you post? Do you know the democratic nomination process?

"Secretary Clinton does not have and will not have the requisite number of pledged delegates to secure the nomination"