Dissenting in Lawrence v. Texas, Justice Scalia stated that, under the Due Process Clause, if an asserted liberty is a "fundamental right," it triggers "strict scrutiny" that almost automatically invalidates any statute restricting that liberty. For strict scrutiny requires that the challenged statute, to be upheld, must further a "compelling governmental interest" and must be "necessary" or "narrowly tailored" to doing so. Scalia also wrote that if an asserted liberty is not a fundamental right, it is merely a "liberty interest" that triggers rational basis scrutiny that is so deferential that the Court all but automatically upholds the statute in question. For deferential rational basis scrutiny requires merely that the challenged statute, to be valid, must further a "legitimate governmental interest" and need only be "rationally related" to doing so.
Linda McClain & James Fleming,
The Myth of Strict Scrutiny for Fundamental Rights
Dartmouth Law Journal
Available at: https://scholarship.law.bu.edu/faculty_scholarship/2912