Nate Silver has been hating on Bernie since 2015, but he's generally held off insulting millions of his supporters until now.

What a nice, unbiased "numbers guy".

Nate Silver is a loyal establishment Dem, BUT he can also do simple math.
What set off Silver was articles like this:
Russians launched pro-Jill Stein social media blitz to help Trump win election, reports say

Clinton's numbers have gotten among Bernie Sanders supporters. 60% have an unfavorable view of her. https://t.co/qBPua9pS3a