d. Contracts Clause: Lastly, we find “mere-rationality” review in some aspects of the “Obligation of Contracts” Clause.
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 marry, to vote, 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.
c. Freedom of expression: Next, we move to the area of freedom of expression. If the government is impairing free expression in a content-based way, then the court will use strict scrutiny and will almost certainly strike down the regulation. In other words, if the government is restricting some speech but not others, based on the content of the messages, then this suppression of expression will only be allowed if necessary to achieve a compelling purpose (a standard which is rarely found to be satisfied in the First Amendment area).
d. Freedom of religion/Free Exercise Clause: Lastly, the court will use strict scrutiny to evaluate any impairment with a person’s free exercise of religion. Even if the government does not intend to impair a person’s free exercise of his religion, if it substantially burdens his exercise of religion, the government will have to give him an exemption from the otherwise-applicable regulation unless denial of an exemption is necessary to achieve a compelling governmental interest.