[El Gato]

The Bill of Rights are applicable to the states only through the due process clause of the Fourteenth Amendment.

Then what was the purpose of the "Privileges and Immunities Clause". Every part of the Constitution has meaning, that is fundamental. The authors said it was to apply the fundamental guarantees/protections of the first eight amendments to the states. The Court has disagreed, but that doesn't mean the Court was correct or that some future Court won't finally see the light.

[Unknowing]

Separating the privileges and immunities of a state citizen from the privileges and immunities of a citizen of the United States, I think, started with the Slaughter-House Cases in 1873. Justice Miller made that separation for the Court, according to the decision, partially in order to limit the control of Congress over the states. Thus only "fundamental" rights were deemed incorporated.

The fundamental-ness of those rights was to be weighed, according to Justice Miller in the Slaughter-House Cases decision, weighed according to the standard put forth in the 1823 case of Corfield v. Coryell, a circuit court case: "protection by the government, with the right to acquire and possess property of every kind, and to pursue and obtain happiness and safety, subject, nevertheless, to such restraints as the government may prescribe for the general good of the whole."