Glossary
Rational basis review
The most deferential test courts use, upholding a law if it is rationally related to any legitimate government purpose.
Also called: rational basis test, rational relationship test
Rational basis review is the default standard courts use when a law does not involve a suspect classification such as race or a fundamental right. A law passes if it is rationally related to a legitimate government interest. The challenger bears the burden of proof, and the court may uphold the law based on any conceivable justification, even one the legislature never stated.
Most economic regulation, tax laws and social-welfare rules are judged under this standard, and nearly all of them survive. The Supreme Court established the modern version after the New Deal, in cases such as United States v. Carolene Products (1938) and Williamson v. Lee Optical (1955), which upheld a law favoring optometrists over opticians.
Libertarian lawyers argue that rational basis review gives too little protection to the right to earn a living and to property, pointing to cases on occupational licensing and protectionist regulation. Some courts apply a tougher "rational basis with bite" when a law appears motivated by animus. The standard sits at the bottom of a ladder that includes intermediate scrutiny and strict scrutiny.
Last reviewed November 8, 2026