Of course such determinations should be left to the professionals, our Supreme Leader, the oh-so-popular Congress and the stalwart defenders of liberty and justice: the Courts -- which are all so trustworthy, moral, and competent.. and who would never hide anything under the pretense of "national security" to cover their own asses, to grab more wealth and power, or keep the public from knowing of atrocities and crimes they, their buddies or their lackeys have commited.

In a system where elections are so influenced by money that billions are spent on advertising candidates. Where virtually all the discussion of the candidates is about their personalities and presentation (such as whether a candidate wore a flag lapel, or how he golfed) rather than about their policies and stances on concrete, important issues.

In a system where the majority of those who do vote are embarrasingly ignorant of politics, history, and the candidates and parties for whom they're voting (largely thanks to the horrendous media coverage mentioned above, and the atrocious education system in the United States).

In a system where the elected candidates can do the opposite of what he campaigned on virtually without consequence or most of their constituents noticing (thanks to the media, yet again).

In a system where gerrymandering has effectively guaranteed the seats of most members of Congress, no matter how poorly they perform. (Given the record low approval ratings of Congress, virtually all of them should been thrown out ages ago, but that's not going to happen any time soon.)

In a system where there are only two parties who agree on most issues, and collude to keep third parties and serious alternative from ever being viable.

In a system where the people appointed by the elected/selected politicians get to make decisions outside the (incredibly flawed) legal process, in secret, and with virtually no oversight or accountability to the public.

In a system that tortures prisoners, violates human rights, starts unprovoked wars that kill millions of people.

I'm sorry, but I just don't place much trust in such a system. And I applaud whistleblowers who risk their lives to expose wrongdoings.

Which leaves the president. You can't believe that providing 1 bit of information every four years is sufficient to maintain a democracy, can you?

While there are allowed exceptions, a Republic operates on a default assumption of public access and transparency in government, and the liberty and privacy of the individual. The converse system, where there is a presumption of secrecy in government, and transparency of the individual, is a tyranny, as government, the people's servant, has become their master.

  You can't believe that providing 1 bit of information 
  every four years is sufficient to maintain a democracy, 
  can you?

Oh please, there's enough outrage to go around for a whistleblower publishing stuff that most foreign intelligence services already knew and suspected, and even if it weren't that way still accted accordingly as though was real, but God let the public know, lest they know how tight the chain is.

It is extremely unlikely those documents have anything of strategic value for other nations; it is almost absolutely certain they are important for the public.

No, he's not the ultimate arbiter, that's what the US government tried to be, in secret, until Snowden stepped up. And others with access are free to step up as well.

Snowden didn't do that, the USG appointed him to that role by not doing an adequate job of it themselves. Snowden is merely a symptom, not a cause.