Holy... just wow. Like out of a movie, can't quite believe what I'm watching. Snowden the political candidate? Snowden the mouthpiece? Snowden the hero? I'm looking forward to reading the HN discussion on this.
Pardoning him would set a precedent indicating leaking top-secret documents when you think you have a higher moral purpose is an 'acceptable' thing to do. I'm wholly on Snowdens side in these particular circumstances, but even his case is, sadly, subjective. I believe knowing you could lose your freedom is a healthy filter to ensure people act as responsibly as possible.