Snowden and other whistleblowers, of whom there have been many (many of which paid arguably a dearer price than Snowden did), made it plain obvious to everyone that US intelligence services are doing illegal things abroad and at home. Before that, only tinfoil-hat-types thought so: now everyone knows it. They moved the Overton window a tremendous amount.

I don't think actual change comes from people lobbying for some bill or whatever. It comes from a far more imperceptible shift in the zeitgeist of society, that is then eventually formally reflected in some way or another. For instance the Civil Rights Movement only succeeded because society had already largely shifted, before it had even begun, in a way that made it viable. A Civil Rights Movement in Saudi Arabia isn't going to succeed, because it needs the widespread desire for such to already exist.

And in this regard I think Snowden had a bigger influence on society than anybody or anything in my living memory. Prior to him there was a belief by many that government conspiracies couldn't happen because somehow if there were enough people involved, it'd show up on News at 9 or whatever. He made it clear that such conspiracies, far beyond the bounds of what even the absurd conspiracy theorist might propose, can and do exist. The NSA has friggin spies in World of Warcraft!

That sort of skepticism played a key role in fueling an anti-establishment mindset. And that mindset is what fueled the rise of everything from Trump to the DSA. I'm certainly not claiming those are good outcomes, but merely part of an increasingly visible shift away from the old establishment. And I think this shift will be, in the longrun, good for America. And I think in hindsight, it will be clear that a lot of this change started happening with Snowden.

Snowden's files are the direct reason we have HTTPS everywhere.