Greenwald is a Putin and Assad apologist. I don't give his opinions of democracy much credence.
Well, the problem here is Trump. Trump is the most immediate threat to democracy (as well as to peace, public safety, etc.). It is not a good situation that we are in where we are relying on the "deep state" to check and balance Donald Trump, but it is the situation we are in. In a functioning democracy, where you had a president and a majority party that respected the rule of law and believed in good governance, you wouldn't need the "deep state" to intervene, but instead we have Trump and the modern GOP.
Few journalists (with the exception of those at Breitbart and Fox News or whatever) did more to get Trump elected than Greenwald, so I'm not going to place much credibility in his cry crocodile tears about the "deep state" now that he's gotten his fascist elected.
