Courts have identified the basis for such protection from the due process clauses of the Fifth and Fourteenth Amendments to the Constitution, which prohibit the federal and state governments, respectively, from depriving any person of "life, liberty, or property, without due process of law".

What idea is substantive due process based on?

Substantive due process, although also based on principles of fundamental fairness, is used to evaluate whether a law can be applied by states at all, regardless of the procedure followed.

What amendment is substantive due process?

The Fourteenth Amendment reads, in part, that no state shall “deprive any person of life, liberty, or property, without due process of law.” This applies to the states and to local governments. The Due Process Clause of the Fifth Amendment applies to the federal government.