Democracy is a good idea. But it is neither the only good idea nor the most important one. To protect everyone from governmental mistreatment, the rule of law is much more important than democracy.
Democracy gives voters only limited and slow influence over government. It isn't "government by the people." Governing requires power, power requires organization, and the ability to make day-to-day decisions on behalf of any organization always becomes concentrated in the hands of a few individuals.
This "iron law of oligarchy" was originally formulated by a sociologist who studied democratic political parties.
All governments being oligarchical, democracy merely limits what the individuals who are ruling can get away with. Democracy employs competitive elections where people striving for power bid against one another for voter support. Democracy is rule by SOME people, limited by THE people.
Democracy can usually protect a majority of the people from being abused by government but doesn't prevent government from abusing minorities or disfavored individuals.
Furthermore, people have limited ability to know how to vote in their own interests. They choose leaders based on images projected through mass media rather than on personal acquaintance. These leaders will work within circumstances that couldn't be predicted when they were elected. Voters must guess who will do the best job.
Although voters may replace top officials, this is a far cry from changing government's overall behavior. Like a steamship, government has tremendous inertia — a tendency to keep on doing what it is already doing — and is difficult to turn around.
Only over time can persistent voters steer the political ship in a radically new direction.
Protection from abuses that democracy cannot guarantee is provided by the rule of law. The rule of law, as I understand it, requires that government impose sanctions (deprivations of life, liberty, or property) only upon people duly convicted of violating a truly general rule of action.
To be truly general, legal rules must apply to everyone, not just selected parts of the population. No sanctions can be imposed on black people for actions other races are free to take. Government cannot exterminate Jews or put Japanese-Americans in concentration camps.Government cannot imprison or fine women for actions which men can take freely.
The rule of law's requirement that sanctions be imposed only for violating a really general rule of action protects individuals and minorities. Those who govern must be subject to the same rules, ample motivation not to enact intolerable ones.
And this is true whether or not the government is democratic.
We need to be especially careful not to let existence of democracy become an argument against the need for the rule of law, including its vital procedural requirement, due process of law. All government power, including democratic power, is liable to be misused. As Alexis deToqueville wrote, a generation after the Constitutional Convention of 1787:
"If it be admitted that a man possessing absolute power may misuse that power. . . , why should not a majority be liable to the same reproach? Men do not change their characters by uniting with each other. .... For myself, when I feel the hand of power lie heavy on my brow, I care but little to know who oppresses me; and I am not the more disposed to pass beneath the yoke because it is held out to me by the arms of a million men."
If a presidential administration claims it need not guarantee due process of law (as protected by two separate clauses in the Constitution) because a democratic majority elected it, we must give that administration our undivided. . . suspicion.
Was this what Donald Trump was claiming when he tweeted "The Supreme Court is not allowing me to do what I was elected to do"?
We are born into an existing political order. We generally can't choose the form of government under which we will live. But if we did have a choice and couldn't have both types of protection, it would be rational to prioritize the rule of law over democracy.