You know, maybe Sanders made the right decision by not conceding the primary until the very end. He managed to push forward nearly all of his platform stuff, including stuff that was outright declared by some people as "delusional", like 15$ minimum wage, alongside with breaking up big banks and free public university education.
It sure seems that he didn't lose any political influence by not quitting early. In fact, he may have had much more influence than he would have had otherwise. This is certainly a historical decision on his part, one that may be followed by many more candidates in the future.
... just about every appearance is that he lost a
lot of political influence by not quitting earlier, as well as not handling things during the primary a (fair) bit more adroitly. Those things you mentioned as pushing forward were things clinton was
already intending to push towards, just not quite as rapidly (because, y'know, then it'd be easier to actually get some shit done in a single term) on some fronts. 13-and-a-bit minimum wage, a massive expansion of free uni education for everyone below a certain (pretty damn high) income, etc., etc., etc. Was all shit that was already on the table. In exchange for "concessions" that were basically already happening, he's hurt the chances of a liberal president (and by extension SCOTUS position), lost pretty much any chance of influencing any major cabinet etc. positions, and mostly pissed off many of the people that's basically been trying to do the same goddamn thing he was.
He's
maybe expanded his personal voting base to a degree (but not as much as he
could have, because as I've noted this shit has alienated some of his previous support base) and managed to convince people to try to do some stuff that's probably goddamn stupid on a practical level, and in exchange did a lot of bridge burning with people that not just
could have been allies towards the things he's try to get, but
were (and still are, but you can pretty much guarantee it's not going to be so in tandem with sanders very much at this point), and generally turned a fair chunk of people that already
weren't largely against his rhetoric style and whatnot.
Basically any gains you're seeing are significantly smaller than they probably could have been, and some have quite possibly turned things that
could have been victories outright for his platform into pyhrric ones at
best. A number of the decisions he's made, particularly near the end of the primary, have been frankly fucking stupid, particularly on any level that isn't kinda' distasteful (i.e. not egotism or personal gain or whatev').
And seriously, I say all this as someone that came into this primary pretty damn supportive of the guy, and was kinda' trying to stay positive on the man for most of the primary. I've
really wanted to support someone as verbally (if not functionally) left-wing as he is. But dude done fucked up. My opinion of him as a political operator is now pretty much nil, and the impression of character he was giving before has been eroded to hell.