But anyway, it's that "privileges and immunities" clause that's been misapplied, in my view, because privileges and immunities of citizenship are not the same as rights of people.
... The Due Process Clause of the Fourteenth Amendment, ratified in 1868, declares, "[N]or shall any State deprive any person of life, liberty, or property, without due process of law" (§ 1). This clause limits the powers of the states rather than those of the federal government.
The Due Process Clause of the Fourteenth Amendment has also been interpreted by the Supreme Court in the twentieth century to incorporate protections of the Bill of Rights, so that those protections apply to the states as well as to the federal government. Thus, the Due Process Clause serves as the means whereby the Bill of Rights has become binding on state governments as well as the federal government.
... The modern notion of substantive due process emerged in decisions of the U.S. Supreme Court during the late nineteenth century. In the 1897 case of Allgeyer v. Louisiana, 165 U.S. 578, 17 S. Ct. 427, 41 L. Ed. 832, the Supreme Court for the first time used the substantive due process framework to strike down a state statute. ... The Allgeyer case concerned a Louisiana law that made it illegal to enter into certain contracts with insurance firms in other states. The Court found that the law unfairly abridged a right to enter into lawful contracts guaranteed by the Due Process Clause of the Fourteenth Amendment.