Look, I'm not a lawyer but I've written over 500 articles for a law blog, including this issue and the fact is, the blatantly partisan and political move would have been to charge her. Law is based on precedent and the only precedent for deleting classified information on emails is no prosecution, ever. (Don't even get me started with Kissinger's precedent in the State Dept. as well, Hillary was not close to that level of corruption).
Obviously she managed her own server to avoid FOI requests, which while an extreme loophole, is not illegal as of now. She rode the line, but didn't cross it, which has been well known among legal circles for several years now. She isn't incompetent, she isn't stupid, she rode a loophole to its exact boundary.
Pretty much any lawyer is going to tell you the same thing...everything else is political and as Socrates famously said, 'the masses are asses.'
Take it for what it is, it doesn't make me like her any more or any less, she is an extreme opportunist, calculating and cold, but I do believe in my heart that she cares for common folk (to what degree is debatable). Trump on the other hand, is unstable, unfit to lead, and cares about nothing more than Donald Trump and his family.
That is what this whole issue is about, no bull....glad I could help.