Matt Breunig has a good post on why millennial women are so drawn to the Sanders over Clinton. On the policy side, however I see another angle, and it’s exemplified by the difference in their college plans.
Both Clinton and Sanders offer free college of a sort in their plans, with Clinton subsidizing consumers in the current system and Sanders supporting a more traditional (read pre-1980) approach to the state system.
But in building out the current system, Clinton values choice over the reduction of complexity. It continues the Rube Goldberg machine of FAFSA, loans, means-testing, pegging parental income to one year that may not be indicative.
One lesson progressives could learn from Sanders is that choice and access are often opposing forces. Choice creates complexity which reduces access, especially for those people already balancing many obligations and for those people unfamiliar with how to navigate the system (read: lower SES populations, etc).
While there are a number of headwinds against a Clinton presidency, fixing the education plan would be easy. There is already broad bi-partisan support for free community college at the state level, and this forms a good platform to expand state-provided education. Sanders is correct as well that Harvard does not need more tax dollars (and research shows that additional support just reduces endowment-provided aid). She likely cannot pivot now, but if she really wishes to gain the youth vote she will fix the Rube Goldberg mess neoliberalism has made of educational funding when she gets into office, not build on it.