You can't write rules against bad actors. There will always be some legal loophole a bad president can invent to exploit. if not for administrative warrants we would see some other creative (read: illegal) use of executive power.
The only option is to not elect someone that doesn't respect rule of law. And since I know some enlightened "centrist" will play the both sides game: What's 1 thing any previous president has done equivalent to violating posse comitatus.
I strongly disagree. You should always write rules under the assumption it will get in the hands of the worst people. If there is a 'become god-emperor' lever in your supposedly democratic government system then it is a shitty system.