I don't know the relevant law (or really much of any law) in detail, and hope that someone here who does can express an informed, educated opinion.
Stuff that is TS/SCI (Top Secret / Sensitive Compartmented Information) is what commonfolk call state secrets. It's stuff that is so important to national security that we call people who share it with non-cleared foreign folks spies and charge them with treason, and the punishment is up to and including death. It is a Big Frelling Deal. That's the heavy hammer that's being threatened and used against Assange, Snowden and Manning for doing the same thing, albeit on a larger and wider scale. Just storing it on a non-secure system within the government is considered Bad Form and subject to disciplinary action or worse. Printing it out and taking it home is Particularly Bad Form. Doesn't forwarding it over private email systems amount to all of that and much more?
Why aren't we calling for Hillary's political head, if not sending her to jail?