Rule of law is a principle under which all persons, institutions, and entities are accountable to laws that are:
Publicly promulgated. Equally enforced. Independently adjudicated.
The seven principles of the Constitution, the guidelines for the Founders, were
This is a government in which the people rule. The people can elect members to Congress and can choose the president. The idea of “popular sovereignty” is found in the Preamble of the Constitution.
The word “republicanism” means a representative government where citizens can vote for people who share their opinions and views. Republicanism means the power rests with citizens who can and do vote. Then, elected representatives use their power to make laws.
Article IV, Section 4 of the Constitution states "The United States shall guarantee... Republican Form of Government…and protect each of them against invasion, and on application of the legislature, or of the executive (when the legislature cannot be convened) against domestic violence.
The word “republicanism” should not be confused with the Republican political party.
The word “federalism” means that the state governments are under a central government. The government of the United States is called a federal government (a national government). The national government and the state governments share power.
Prior to the ratification of the Constitution, every one of the thirteen original states had its own Constitution. The Tenth Amendment set the guidelines for federalism in the United States.
Article IV establishes the relationship between the states and the federal government.
In the U.S. Constitution, there are three branches of government that make, enforce, and interpret laws. Under the separation of powers, each branch of government has a unique function.
The legislative branch makes the laws and has the power to pass, change, and repeal laws. Article I of the Constitution establishes the legislative branch (the House of Representatives and the Senate).
The executive branch carries out the laws and is responsible for running the government day to day. Article II establishes the executive branch, that is headed by the president.
The judicial branch interprets the laws and settles arguments. Article III establishes the judicial branch (a system of courts and judges).
Each of the three branches has the power to check or control the powers of the other branches.
Under the separation of powers, each branch of government has a specific function. This way, no one branch of the government can be too powerful.
The Declaration of Independence says that governments get "their just powers from the consent of the governed," meaning that the people elect their representatives and that everyone is bound by the "supreme law of the land." This means that no one, not even the president, is above the law.
The personal freedoms of the people are guaranteed by the Bill of Rights and cannot be taken away by the central government.
Adapted from: http://www.government-and-constitution.org/us-constitution/7-principles-of-the-constitution.htm