I think the biggest reason the Pentagon Papers leak was so much more impactful was that there was already a much larger fraction of the citizenry sensitized to

I think the biggest reason the Pentagon Papers leak was so much more impactful was that there was already a much larger fraction of the citizenry sensitized to the issue and inclined to act on what was revealed. Someone else made the point that Ellsberg was also lucky in that the information he wanted to leak was already collected into a document. It's hardly Snowden's fault that he didn't have this luxury. Anyway, for the record, I don't disagree with the argument that a highly placed insider could have leaked better-selected material and overall been more effective -- albeit at a level of personal risk that can only be described as extreme (and much greater than what Ellsberg faced). In the event, however, no such person chose to leak the most important material that Snowden leaked. The thrust of your argument seems to be that Snowden should have said to himself, "I'm just an IT lackey; what do I know?" and not attempted to rise to this occasion. That would be where we disagree. Yes, in some hypothetical alternate world, there might have been a better-placed leaker who would have made better choices and been more careful. But Snowden had no way to know that any such person would ever appear, and neither do you.