> no matter how right he believed himself to be.
Does it change anything for you if it wasn't just his opinion, but some sort of majority consensus instead—even if that only arrives in the history books? (Only asking in principle, as a hypothetical—not making the claim that Snowden in fact was right.)
There seems to be a fundamental problem with what you're proposing here—of course the vigilante approach is riddled with obvious issues too, but I just want to point out that what you're describing isn't clearly an effective way of dealing with things either.
You're basically saying the system works and we should trust it to evaluate and handle Snowden correctly: we have Congress, and they'll make the right choices if not the president.
But, the giant government programs exposed by Snowden are already a striking example of how we can't rely on Congress, at least to handle this matter correctly. Why would we assume the same entity which created the problems that were exposed is going to then handle the exposer fairly?
(I don't know the precise link between the exposed programs and Congress—so maybe they are separate/unrelated enough that my suggestion is inaccurate.)