(1) Have freedom of the press so that the press can put out the information needed for an informed citizenry.
(2) Have freedom of speech and assembly so that the citizens can learn, discuss, and decide.
(3) Have the Bill of Rights so that the government can't just run roughshod over the citizens.
(4) Have three branches of government so that there can be checks and balances and keep, say, the Executive Branch from becoming dictatorial, self-serving, self-perpetuating, and tyrannical.
(5) Have the President and the Congress elected by the citizens, directly or nearly so and, thus, have them elected out'a there when the citizens don't like them.
Then, presto, to solve the problems, citizens just need to become informed and, then, behind some curtains pull some levers. Done. All the powerful, wealthy, connected, crooked dirt bags in government float belly down down the Potomac River.
Net, we just need to become informed and pull the levers.
And, there's another way: Bring law suits, e.g., citing the Fourth Amendment.
So,
Q. Go to war in Syria?
A. Not without money voted by Congress.
Q. Implement ObamaCare?
A. Not if the citizens and/or courts don't like it.
Q. NSA spying on US citizens?
A. Not if citizens vote to stop that stuff and/or court cases get brought and are successful.
Q. The spying on US citizens as in the OP?
A. Not if citizens don't like it and/or there are suitable court cases.
Q. US Customs taking mobile electronic devices of US citizens and extracting and keeping all the data?
A. Not if, right, the usual, citizens and courts stop it.
Etc.