The same way you make sure democracy or the majority has the right "fundamental principles"..

well, it's a government, so it basically just works until it doesn't. then you get a revolution. and a new government, that works until it doesn't.

nothing is guaranteed. it's just humans.

I don't think anyone is advocating military coups in the general case.

Control Hollywood.[0]

[0] http://www.thewritersjourney.com/hero's_journey.htm#Memo

Reduce the standing army and replace it with conscripts.