Strict Scrutiny

Strict scrutiny is the highest of the three tiers of judicial review used by U.S. federal courts when evaluating the constitutionality of government action under the Equal Protection and Due Process Clauses of the Fourteenth Amendment, as well as under the First Amendment. To survive strict scrutiny, the government must prove that the challenged law (1) advances a compelling government interest and (2) is narrowly tailored, meaning it uses the least restrictive means available to achieve that interest.

Courts apply strict scrutiny in two main situations:

• When a law classifies people based on a suspect classification, such as race, national origin, or alienage.
• When a law burdens a fundamental right, such as voting, interstate travel, marriage, or the free exercise of certain First Amendment freedoms.

The doctrine traces its modern origin to United States v. Carolene Products Co. (1938), whose famous Footnote Four suggested heightened review for laws affecting "discrete and insular minorities." It was articulated more explicitly in Korematsu v. United States (1944), which paradoxically upheld Japanese-American internment despite invoking the standard. Later landmark applications include Loving v. Virginia (1967), striking down anti-miscegenation laws, and Adarand Constructors v. Peña (1995), confirming that all racial classifications by the federal government—including affirmative action—trigger strict scrutiny.

In practice, strict scrutiny is famously difficult to satisfy; legal scholar Gerald Gunther in 1972 described it as "strict in theory and fatal in fact," though empirical studies (notably Adam Winkler's 2006 analysis) have shown the standard is survived more often than the aphorism implies, particularly in national security and prison cases.

Strict scrutiny sits atop a tiered framework that also includes intermediate scrutiny (applied to sex- and legitimacy-based classifications) and rational basis review (the default deferential standard). Outside the United States, comparable proportionality analyses exist in German constitutional law and under the European Convention on Human Rights, though the terminology and structure differ.