Strict scrutiny is the most stringent standard of judicial review used by U.S. courts reviewing federal law. Along with the lower standards of rational basis (reduced scrutiny) review and intermediate scrutiny, strict scrutiny is part of a hierarchy of standards courts employ to weigh an asserted government interest against a constitutional right or policy that conflicts with the manner in which the interest is being pursued.
Strict scrutiny is applied based on the constitutional conflict at issue, regardless of whether a law or action of the U.S. federal government, a state government, or a local municipality is at issue. It arises in two basic contexts: when a "fundamental" constitutional right is infringed, particularly those listed in the Bill of Rights and those the court has deemed a fundamental right protected by the liberty provision of the 14th Amendment; or when the government action involves the use of a "suspect classification" such as race or national origin that may render it void under the Equal Protection Clause. These are the two applications that were anticipated in footnote 4 to United States v. Carolene Products Co.
To pass strict scrutiny, the law or policy must satisfy three prongs:
- First, it must be justified by a compelling governmental interest. While the courts have never brightly defined how to determine if an interest is compelling, the concept generally refers to something necessary or crucial, as opposed to something merely preferred. Examples include national security, preserving the lives of multiple individuals, and not violating explicit constitutional protections.
- Finally, the law or policy must be the least restrictive means for achieving that interest. More accurately, there cannot be a less restrictive way to effectively achieve the compelling government interest, but the test will not fail just because there is another method that is equally the least restrictive. Some legal scholars consider this least restrictive means requirement part of being narrowly tailored, though the U.S. Supreme Court generally evaluates it as a separate prong.