What did the founders mean by the term “rule of law”?

The term "rule of law" means that everybody should follow what the law dictates. Nobody is exempted from following the written law unless explicitly stated as an exemption to the law.

"Rule of law" is very important legal principle in governing a nation. Since, people in the government is elected to a limited term, the only constant in the government is the laws it has passed. Therefore, whoever is seated in a government position must adhere to the letters of the law and not make his own laws based on his personal whim.