The director of the NSA lied while under oath to congress, and nothing happened. As far as I'm concerned, what 3 letter agencies say publically is irrelevant.
However many people somehow simultaneously hold the belief that these agencies should continue to exist, are deserving of our taxpayer dollars, and are generally Good Guys who happen to do bad things sometimes. Perhaps it's just too exhausting to consider the extent of corruption in the USA.
My guess is that most Americans would expect that they sometimes do things that aren't legal, but that generally they are at least intending to do it with the best interest of our country in mind. That second part is the primary reason why they aren't being wholesale shut down, and why they're able to get away with things like lying to congress.
Two thoughts:
1) Even if most Americans decided they needed to be shut down, how would we enact that? It seems to me there are very few people who have that power, and even if a great majority of us wanted it, we have no way to enact it (and no way of knowing if it was actually enacted; we could be told it had been done, but that could easily be an inscrutable lie)
2) If they were actually shut down, what would the people who worked there do? Highly intelligent, skilled, with low morals, used to performing nefarious activities; they would go on to be in shadow NGOs, organized crime, reform under other names, etc.
Prison time, like any other criminal enterprise.
If you took the NSA's "incidentals records" database and said you were purposely tracking Americans, it would obviously be unconstitutional. So they created a loophole to claim the obviously illegal act is allowed.
I disagree. I think they absolutely believe they are doing what is best for the country, but without actual accountability and meaningful outside oversight and input, I would say it is far more likely they have become myopically focused. That they are unable to accurately judge or weigh the effects of persistent surveillance against one’s own citizens and how that negatively impacts a free and open democracy and a government that feels accountable to its citizens, vs their own very skewed perspective of looking at nothing but “threats” and thinking about nothing but threats, and planning for nothing but threats. The “everything is a nail to a hammer” saying comes to mind.
Abolish the (secret) police?
It's basically the same debate; people need to feel that the threat from the "protectors" is greater than the threat they are allegedly protecting against before something gets done. And, realistically, being spied on by the CIA is fairly low down the average person's list of problems. Even the citizens who are most directly threatened by American policing would prefer dealing with the immediate threat of street violence and gunshot murders by the police than the distant, nebulous threat of the CIA plane over the protests.
Having your candidate spied on by the CIA, FSB, Met police, or Jim-Bob's Laptop Repair Shop is more of a problem.
Objectively, even in 2001 terrorism was a negligible risk compared to everyday risks, and subjectively, there hasn't been a major terrorist attack for years. The only reason mass surveillance exists is a rationale by the US state that "more power is good". This may apply to the US army, but not to the spies.
Also, like you say, once the american spies start to (pun intended) "Interfere in american elections", then the problem affects everybody with P=1. Personally I could live with it trump were the only candidate they work against, but if they do it to trump, they likely do it to others. (I see no evidence of interference or other abuse of collected data currently, but I think it's dangerous to give them the power to collect all this info that can in principle be abused for selective prosecution and/or blackmail).
Also, it affects not just politicians, but also corporate execs, who can be further pressured using the other means of the state, and who themselves have power the state can deputize.
A democracy should have the surveillance powers that are proportionate to the benefit from these powers and no more. There is a positive value in minimizing state surveillance power; this concept seems lost on america. (In fairness, it seems lost on conservative parties worldwide.)
Their mindset: we own the United States of America, and the rest of you are just sheep. We are doing shepherd's job and you don't need to understand it. We are doing wolf's job because there are wolves at the gate so we better fight back with bigger teeth. We the people do not include your ordinary sheep, and only the privileged ones are "people".