Earlier quoted context omitted.
I'm for a pardon for Snowden, but not Manning. Snowden released info on a deeply classified and unethical program, targeted to dismantle the programs in question. Manning carte blanche released TONS of data about TONS of things, trusting only Wikileaks to filter out sensitive data.
Snowden carte blanche stole and gave up "TONS of data about TONS of things", trusting only Greenwald, et al to filter out sensitive data.
Edit: That being said, if we ever do get evidence that China or Russia did manage to get that data during his trip there, I'd change my tune immediately. That would be high treason, at least if it was intentional.