Specifically the cooling-off period after holding high office.

I think, if any executive or appointed official ever declares a state of emergency, or other euphemism for curtailing people's freedoms and rights in the name of the greater good, he should immediately and automatically be out of office at the end of the period, and be imprisoned for a period of not less than the duration of the emergency. No stigma or lingering punishment afterward, full restoration of his civil rights, but also be barred from elected or appointed office for five or even ten years, depending on how high said office is. And the same sort of thing for declaring war, or deploying the military for more than 90 days.

Then we can have people really think seriously about just how emergent a situation truly is before rushing to pull the trigger on this sort of thing. What's more, people will be more inclined to respect the decision, and the person making it, if they know what price he's paying in the name of that greater good.