We could sure use a moral-based meritocracy about now.
As you know, the US Constitution left it up to the individual states to determine how much power the people shall have in their rule, and how that power shall be shared amongst the people.
Yes and no. The basis for determination of how much power the people shall have in the United States, and how that power would be shared amongst the people, comes from the Declaration of Independence, written by Thomas Jefferson and counseled upon by Benjamin Franklin, John Adams, Robert Livingston, and Roger Sherman (the "Committee of Five"). These men would largely play major roles in establishing the very first United States constitution - the Articles of Confederation - and then the subsequent improved version we today know as our Constitution.
After the War of Independence was won, the various 13 colonies became states of people, and established their own individual state constitutions, most all of them incorporating the same understanding that "all men are equal" with unalienable rights and freedoms. Of course, with the issue of slavery, there were stated exceptions.
The Constitution contains what is called "The Comity Clause", also more formally the "Privileges and Immunities Clause", which is Clause I of Section II within Article IV of the Constitution. This was carried over largely from the Articles of Confederation it served to supplant.
The word "comity" is not a well-used word these days, and has largely been forgotten in the American language, but it has popped up various times in politics - particularly in Congressional speeches on the floors since 2016. Congressmen stating how there is no longer the "comity" between the political parties across the aisles, and how Congress needs to return to the days of greater comity in order to better do their jobs of representing the people.
The "Comity Clause" was named so, because at the dawn of this nation, there was considerable distrust amongst the peoples of the various colonies/states. One needs to put their mind-set into what life was like in the late 1700s - where the only means of travel was by animal or by foot. Going from one end of a state to the other took days on horse-back - going from say, Raliegh to Philadelphia or Boston took weeks or as much as a month. People would be born, live and die of old age never leaving their counties they were born in. Peoples from other states were viewed as "strangers" to be held with suspicion and watched closely, thought of as only logically being where they were - far from their homes - due to dubious means and reasons.
Because of this nature, to be in a state like SC during the Revolutionary Era, and have someone come up and say "I'm from NC, I'm from PA, I'm from NY, I'm from MA" - would be almost the same perception as someone coming up and saying "I'm from Great Britain, I'm from France, I'm from Spain, I'm from Germany". They were that foreign.
The "Comity Clause" was intended to ensure that the rights of citizens were not infringed upon simply by crossing out of their states into other states, due to these logistical prejudices. That citizens of say NC would be held to certain laws in NC, but a citizen of SC would be held to different laws in NC.
The "Comity Clause" made it Constitutional Right that citizens from other states would be held equally to the same laws as citizens of each state. That ALL citizens had the right to travel across state borders and throughout each state without the need for passports, papers of identification, or the need for permission from state authorities. They had the right to own property in each state they were not citizens of, and to conduct commerce in each state.
This was a Constitutional mandate of equality of freedoms, rights, and liberties for all citizens of the states. It is also considered to be a Right which the Constitutional intends to be administered by the states of the Union, as since the policing of such could only be effectively carried out by the state authorities. But it has been constitutional right since even before the US Constitution existed.
After the ratification of the Constitution, the Bill of Rights that we today refer to as the first ten Amendments to the Constitution were added. Those rights explicitly describe what powers the people of this nation shall have, and how those powers shall be shared amongst the people. The 10th Amendment goes to explain the separation of powers between federal and state government.
It states essentially that ALL powers given and NOT given (wherever in the Constitution it says "thou shall NOT have") within the Constitution, shall be "national powers", otherwise known as federal law - and that all powers not referenced as given or NOT given thereafter would be state powers, or state law.
An example is the common protestation of "Sovereign Citizens" who say they have constitutional right to operate their motor vehicles without a license or registration, referring to the Privileges and Immunities Clause above and the "right to travel". The right to travel can only refer to the right of traveling by foot or animal power. The automobile was more than a century away from being invented when the Constitution was ratified. This is why it's forever been stated "driving is a privilege, NOT a right".
The explicit wording that all citizens have equal rights didn't come to the US Constitution until after the Civil War, with the 14th Amendment. It contains what is called the "Equal Protection Clause", in Section I which states:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
The reference to the "Privileges and Immunities Clause" here is obvious, and note the 2nd sentence where it begins with "No State shall make...."? This is an example of a power given or NOT given to states, and therefore is constitutionally prohibited from state governments establishing it as a state power or law. So in effect, the 14th Amendment is Constitutional Right that all U.S. citizens shall have equal protection under the law......