The United States needs protection from the people protecting it, always has, and always will. The character of the president isn't the issue. Neither are the individuals running the FBI, CIA, NSA, JSOC, or the Department of Homeland Security. It wouldn't matter if the national-security state was staffed from top to bottom with people I could hand select based on my esteem for their character.
Letting them operate in secret would still be dangerous.
That conclusion isn't something I've derived in the abstract from political philosophy. The best reason to mistrust the national-security state is its track record. Abuses at the FBI, CIA, and NSA go back a long way, as any student of the J. Edgar Hoover era or the Church Committee report can attest in shocking detail. There's no reason to think that generation was more prone to misbehave than ours. But one needn't look to past generations to find good reasons for mistrust.
The War on Terrorism is full of them.
~ from Why Does Anyone Trust the National-Security State? by Conor Friedersdorf ~
There is another reason not to trust the national-security state and each of us can ascertain this reason by looking no further than the end of our nose. When we ourselves operate in secret, are we paragons of virtue?
The answer is almost always NO, not even close.
It is a human penchant to try to get away with as much as we think we can get away with. A person, group or entity can get away with a heck of a lot when operating in secret. When nobody knows what we're up to, it's like a green light to be up to more things than you can shake a stick at. So, it is illogical to think that government leaders and their minions would behave any differently.
This is why many of our laws (mores too) involve varying degrees of constraint or outright prohibition. Left to our own devices, most humans would run roughshod over everyone else. In order to live together in relative peace and harmony, we have created [imperfect] rules to constrain each other from non-harmonious behavior. Those who operate outside of the rules in secret are the most dangerous. History attests to this fact over and over and over again.