What does "no one is above the law" really mean?

"No one is above the law" means that the rules bind everybody, including the people who make and enforce them. That is the heart of the rule of law: laws should be clear, public and consistent, people should be able to take their case to fair, independent courts, and the government itself must obey the law. Its opposite is the rule of man, where a person or group simply rules as they please.

The idea is ancient. Aristotle wrote that it is more proper for law to govern than any one citizen. The Upanishads, from India, put it even more bluntly: the law is the king of kings, and no one is higher than the law, not even the king.

The modern phrase grew out of fights with kings. In 1644 the Scottish theologian Samuel Rutherford published a book called Lex, Rex, Latin for "the law is king", turning the old formula "the king is law" upside down to argue against the divine right of kings. In 1776 Thomas Paine made the same point in Common Sense: in absolute governments the king is law, but in free countries the law ought to be king.

There is a subtle trap in the idea. A government can use laws without being bound by them. China's ancient legalist school promoted "rule by law", a powerful legal system that still placed the emperor above it. Under rule by law, law is a tool of the rulers; under the rule of law, it is a check on them. The difference is the whole point.