I think Hillary will fail to win the Democratic party's nomination, and it won't be because of sexism either. (That would be a factor in the Presidential election, and she won't be getting to that level anyway).
No, Clinton is competent, experienced and efficient, and most people see her as such. That's the problem.
Imagining a world where Hillary Clinton is in charge takes one back to one's childhood where one's mother was in charge - "Do your homework!", "Clean up your room!"
Mom knows best. But we're adults now, mom. And we enjoy our adult freedom to keep our surroundings messy and not do our homework once in a while.
Nobody will vote to go back to their childhood - and its powerlessness. Even if mom was around to take care of everything.