b. Substantive due process: Next comes substantive due process. So long as no “fundamental right” is affected, the test for determining whether a governmental act violates substantive due process is, again, “mere rationality.” In other words, if the state is pursuing a legitimate objective, and using means that are rationally related to that objective, the state will not be found to have violated the substantive Due Process Clause. So the vast bulk of economic regulations (since these don’t affect fundamental rights) will be tested by the mere-rationality standard and almost certainly upheld.
c. Equal protection: Then, we move on to the equal protection area. Here, “mere-rationality” review is used so long as: (1) no suspect or quasi-suspect classification is being used; and (2) no fundamental right is being impaired. This still leaves us with a large number of classifications which will be judged based on the mere-rationality standard, including: (1) almost all economic regulations; (2) some classifications based on alienage; and (3) rights that are not “fundamental” even though they are very important, such as food, housing, and free public education. In all of these areas, the classification will be reviewed under the “mere- rationality” standard, and will therefore almost certainly be upheld.
d. Contracts Clause: Lastly, we find “mere- rationality” review in some aspects of the “Obligation of Contracts” Clause.
2. Strict scrutiny: Here are the various contexts in which the court applies strict scrutiny:
a. Substantive due process/fundamental rights: First, where a governmental action affects fundamental rights, and the plaintiff claims that his substantive due process rights are being violated, the court will use strict scrutiny. So when the state impairs rights falling in the “privacy” cluster of marriage, child-bearing, and child-rearing, the court will use strict scrutiny (and will therefore probably invalidate the governmental restriction). For instance, government restrictions that impair the right to use contraceptives receive this kind of strict scrutiny.
b. Equal protection review: Next, the court uses strict scrutiny to review a claim that a classification violates the plaintiff’s equal protection rights, if the classification relates either to a suspect classification or a fundamental right. “Suspect classifications” include race, national origin, and (sometimes) alienage. “Fundamental rights” for this purpose include the right to vote, to be a candidate, to have access to the courts, and to travel interstate. So classifications that either involve any of these suspect classifications or impair any of these fundamental rights will be strictly scrutinized and will probably be struck down.