A. Historical overview: The Fourteenth Amendment provides that “[n]o State shall make or enforce any law which shall … deny to any person within its jurisdiction the equal protection of the laws.”
1. Historical purpose: This Clause, like all parts of the Thirteenth, Fourteenth and Fifteenth Amendments, was enacted shortly after the Civil War, and its primary goal was to secure free and equal treatment for ex-slaves. But from the beginning, the courts interpreted the Clause to “impose a general restraint on the use of classifications, whatever the area regulated, whatever the classification criterion used.” Gunther (10th Ed.), p. 676.
2. Clause before Warren Court: Prior to the Warren Court, the Equal Protection Clause played only a very minor role with respect to classifications based on grounds other than race and national origin. So long as the means used by the legislature (i.e., the classification) reasonably related to the legislature’s purpose, the statute was upheld. Very little attention was paid to whether the legislature’s purpose was itself valid. Gunther & Sullivan (13th Ed.), p. 629.
a. Contrast with due process: Contrast this limited view of the Equal Protection Clause with the broad reading given to the Due Process Clause during the early part of the last century (see supra, p. 166). The Court was much more likely to strike an economic or social-welfare statute on substantive due process grounds than on the grounds that the classifications made in the statute denied equal protection.
3. Key clause in Warren Court: But under the Warren Court, the Equal Protection Clause gained new “bite,” and became the most important clause for ensuring a broad range of individual rights against legislative encroachment.