That may not be possible given the category of law he's charged with. Since his leak did damages to espionage programs that are undisclosable (under classified information law), prosecuting him fairly may not be compatible with the American system of justice as laid out in the Constitution. No real way to do it without building a "star court" with privileged access to classified information, that can therefore not be a randomly-chosen jury of his peers.
... which, one could argue, is a problem with the way the US runs espionage.
The parts where we have public defenders that cannot provide adequate representation, plea bargains that ruin any chance for real justice, bails set at outrageous amounts, prison sentences that are ridiculous by most any other first world country standard, contempt of court used to keep people in jail for over a decade, the list is miles long. The judiciary system is thought by some to be the most political of the branches of government and it shows.
It seems few of those apply to Snowden -- he wouldn't need a public defender, he probably wants a trial rather than a plea bargain, I'm not sure if there's a systemic problem with outrageous bail but Snowden is a textbook case for flight risk, ridiculous prison sentences -- perhaps, but just because a law is harsh doesn't mean that that law is applied unfairly.
The point is that the outcomes of actual trials are weighted towards too much punishment as a result of having the plea bargain system. We're disincentivizing people to actually have their day in court.
How about the existence of "setting an example" sentences, which would absolutely happen to Snowden?
