It absolutely matters. Without those controls you have a democracy in name only. You could quite happily rig elections, arrest opponents, suppress the population etc, while still claiming to be 'democratic'.
There is nothing undemocratic about those thing as long as a majority of people agree to them - though with rigged elections, you might not be democratic for very much longer. "Democracy" is not synonymous with "respecting my values and human rights."
If enough Americans were sufficiently upset about the NSA, it would be gone. They aren't. It's not even a significant election issue.
That requires that people are informed and able to comprehend the ramifications of their choices. Consider this: Is it still democratic if those who happen to be in charge are busy lying to and hoodwinking a poorly informed 'electorate'?
As for the rest of your comment, it is not democracy simply because a majority agree it is. http://en.wikipedia.org/wiki/Democracy
In short, it really looks like some parts of the US government actively work to keep reporting very favorable or non-existent.
edit - This also makes sense from looking at the word. Democracy is rule by the 'demos', which means 'the people', which includes the minority. Rule by the majority is ochlocracy, from 'ochlos', meaning 'the mob'.
Are we sure of that? Wisconsin Senator Russ Feingold lost his re-election bid. He was the only Senator to vote against the PATRIOT Act in 2001.
Colorado Senator Mark Udall lost his 2012 re-election campaign after being a total gadfly in the Senate Intelligence Oversight Committee.
It strikes me that the NSA is a significant election issue, just not to the voters.
Also, you're kind of arguing about a technicality in the definition of "democratic". Our elected reps often act un-democratically. I hope this is to prevent tyranny of the majority, but I fear that it's just legislative capture.
You've just managed to explain quite succinctly why it isn't a significant election issue.