Privileges and Immunities Clause
There has been some debate over the meaning of the Privileges and Immunities Clause with several possible original meanings. A question arises as to whether the clause meant that all state laws should be applied equally to its citizens or that state laws should have certain substantive content. The substantive view can be further divided into two categories. One view is that these privileges and immunities include all of the rights in the Constitution, including the Bill of Rights. Thus, this view sees the purpose of the Privileges and Immunities Clause as applying all of the rights in the Constitution to all of the states. Another view is that it only meant to make the Bill of Rights applicable to the states.
In Corfield v. Coryell, 6 Fed. Cas. 546 (No. 3,230)(C.C.E.D.Pa., 1823), an early case concerning the Privileges and Immunities Clause, found that the Clause protects certain fundamental rights of all citizens. However, in Slaughter-House Cases, 83 U.S. 36 (1873), the Supreme Court rejected that interpretation, holding that the privileges of national citizenship were substantive, but they came about as a result of the federal government, the Constitution, or other laws. The fundamental natural rights were not included, and thus the equality function of the Privileges and Immunities Clause was taken over by the Equal Protection Clause and the substantive functions were taken by the Due Process Clause. Aside from one case that was later overruled, the Supreme Court did not use the Privileges and Immunities Clause as the basis for decisions until 1999 with Saenz v. Roe, 526 U.S. 489 (1999), where California set welfare benefits for new residents at a certain level equal to what their former state provided for the first year of residency in California. The Court decided that part of the fundamental right to interstate travel was for new citizens of a state to be treated like other citizens of the state.
Due Process Clause
The Fifth and Fourteenth Amendments both contain a Due Process Clause, although the Fourteenth Amendment applies explicitly to the states. The Supreme Court has interpreted the Due Process Clauses in both articles as having the same meaning, as Justice Frankfurter describes in his concurrence in Malinski v. New York, 324 U.S. 401 (1945): "To suppose that "due process of law" meant one thing in the Fifth Amendment and another in the Fourteenth is too frivolous to require elaborate rejection."
Due process is generally understood to contain two concepts: procedural due process and substantive due process.
Procedural Due Process
Procedural due process guarantees fairness to all individuals. This fairness might require different elements to the accused, including the opportunity to be heard, given notice, and be given a judicial decision with a stated rationale. As a basic rule, the more important the right, the stricter the procedural process must be. The Supreme Court has defined what property and liberty interests are in different cases. In the case Board of Regents v. Roth, 408 U.S. 564 (1972), the Court held, "The Fourteenth Amendment does not require opportunity for a hearing prior to the nonrenewal of a nontenured state teacher's contract unless he can show that the nonrenewal deprived him of an interest in 'liberty' or that he had a 'property' interest in continued employment, despite the lack of tenure or a formal contract."
Substantive Due Process
Although procedural due process is widely accepted, substantive due process is a bit more controversial. Modern debate regarding the substantive due process clause tends to focus on certain liberties which the Supreme Court has interpreted as belonging to citizens, with a large focus on economic liberties, such as the right to create a private contracts.