What is equal protection?

Equal protection is the constitutional principle that government must treat similarly situated people alike under the law. The Fourteenth Amendment's Equal Protection Clause, ratified in 1868, declares that no state shall deny to any person within its jurisdiction the equal protection of the laws. The amendment was a direct response to Black Codes that southern states had enacted after the Civil War to restrict the rights of newly freed Black Americans, and it transformed the constitutional position of every person under state authority.

Although the clause originally bound only state governments, the Supreme Court applied an equivalent rule to the federal government through the Fifth Amendment's Due Process Clause in Bolling v. Sharpe in 1954. The early Supreme Court read the clause narrowly. Plessy v. Ferguson in 1896 upheld racial segregation under the doctrine of separate but equal, allowing southern states to maintain Jim Crow laws for more than half a century.

Brown v. Board of Education in 1954 unanimously overturned Plessy in public schools, declaring that separate educational facilities are inherently unequal. The civil rights movement and the Civil Rights Act of 1964 expanded the principle into private accommodations, employment, and housing.

Modern equal protection doctrine applies different levels of judicial scrutiny depending on the classification involved. Strict scrutiny applies to laws that classify by race, national origin, or alienage. Government must show a compelling interest and a narrowly tailored means. Intermediate scrutiny applies to classifications based on sex or illegitimacy. Government must show an important interest and substantially related means. Rational basis review applies to most other classifications, including age, wealth, and most economic regulations, requiring only a rational connection to a legitimate purpose.

Major equal protection rulings include Loving v. Virginia in 1967 striking down bans on interracial marriage, Reed v. Reed in 1971 first applying meaningful scrutiny to sex-based classifications, Frontiero v. Richardson in 1973 raising that scrutiny, Craig v. Boren in 1976 establishing intermediate scrutiny for sex, and Obergefell v. Hodges in 2015 requiring states to license same-sex marriages. Affirmative action cases including Bakke in 1978, Grutter in 2003, and SFFA v. Harvard in 2023 illustrate the ongoing controversy over racial classifications.