He says that you can't lump superdelegates in with pledged deletates because pledged delegates are "real".
It's true, though. HRC won't have the requisite number of pledged delegates after the District of Columbia votes on the 14th. Superdelegates don't vote until the convention.
No delegates vote until the convention. 
This is like refusing to concede a general election because "the electoral college doesn't vote until December!"
Well, it's true that the superdelegates don't have to make up their minds until the convention, but there's absolutely no reason for them to switch to Sanders when he's losing the popular vote AND the pledged delegates, AND most of them don't want him as the nominee anyway.
