Equal protection clause Summary

  • Last updated on November 11, 2022

Provision of the Fourteenth Amendment to the U.S. Constitution that prohibits certain forms of discrimination.

Thomas Jefferson securely linked the ideal of equality to the U.S. political tradition when he argued in the Declaration of Independence that “all men are created equal.” However, his tribute to equality did not immediately find a home in the U.S. Constitution. No clause within the Constitution guaranteed equal treatment by the law, and in fact, the accommodation of slavery within the original constitutional text amounted to an obvious breach of the principle of equality. Not until after the Civil War (1861-1865), when the Reconstruction Congress attempted to secure the political and civil rights of the newly freed slaves, would equality enter the constitutional vocabulary. The ratification of the Fourteenth Amendment in 1868 added to the Constitution the principle that Jefferson had championed almost a century earlier. Section 1 of the amendment declared that no state “shall deny to any person within its jurisdiction the equal protection of the laws.”Fourteenth AmendmentDiscriminationFourteenth AmendmentDiscrimination

Early Interpretations

In two early cases, the Supreme Court used the equal protection clause of the Fourteenth Amendment to unsettle official patterns of racial discrimination. Strauder v. West Virginia[case]Strauder v. West Virginia[Strauder v. West Virginia] (1880) invalidated a state law that denied African AmericansAfrican Americans;juries[juries] the right to sit on juriesJury composition and size and thus submitted them to trial by juries in which people of their race could not sit. This disqualification from an important civil right, declared the Court, offended the equal protection clause. Later that decade, in Yick Wo v. Hopkins[case]Yick Wo v. Hopkins[Yick Wo v. Hopkins] (1886), the Court held that the Fourteenth Amendment’s equal protection guarantee extended beyond discrimination embedded in the text of laws to racial discriminationDiscrimination, race practiced in the administration of otherwise evenhanded laws.

In other cases, though, the Supreme Court minimized the transformative potential of the equal protection clause in ways that would endure well into the twentieth century. First, in the Slaughterhouse Cases[case]Slaughterhouse Cases[Slaughterhouse Cases] (1873), the Court suggested that the clause, though written in general terms capable of application to many forms of inequality, nevertheless would probably not be applied to matters other than discrimination against African Americans. Second, in the Civil Rights Cases[case]Civil Rights Cases[Civil Rights Cases] (1883), the Court limited the application of the clause to inequalities involving state action rather than private acts of discrimination. By this limitation, the Court deprived Congress of power under the Fourteenth Amendment to address private forms of racial and other impermissible discriminations. Finally, in Plessy v. Ferguson[case]Plessy v. Ferguson[Plessy v. Ferguson] (1896), the Court grafted onto the equal protection clause the separate butSeparate but equal doctrine;equal protection clause[equal protection clause] equal doctrine, which permitted states to maintain systems of racial segregation, even though the significance of these systems was to treat African Americans as second-class citizens and thus deprive them of equal treatment under the laws. The commutative effect of these interpretations of the equal protection clause by the Court was to diminish the clause’s usefulness as a source of constitutional protection from invidious discrimination. Even in the 1930’s, Justice Oliver Wendell Holmes observed that applications to invoke the equal protection clause were the “last resort of constitutional argument.”

Emerging Standards of Review

Though an able commentator on the law of the times, Holmes could not see the future. Beginning in the 1940’s, the Court, chastened perhaps by the alarming spectacle of Nazi racism toward Jews,Jews;Holocaust reinvigorated the equal protection clause. It did so by establishing two broad categories of cases in which the clause would prove to be most protective against forms of official discrimination. The narrowing of the clause’s potential reach in this fashion was necessary because laws routinely classify individuals differently for a variety of purposes and thus discriminate among individuals. State traffic laws allow seventeen-year-olds to obtain a driver’s license but not eight-year-olds. State universities grant admission to those who have graduated from high school or obtained comparable credentials but refuse those who drop out early and never make up their educational deficits. In these and innumerable other respects, laws discriminate without offending typical notions of equality. The task of the Court, beginning in the 1940’s, was to identify particular forms of discrimination that might be singled out as constitutionally troublesome in a sense not shared by the kind of routine discriminations that characterize ordinary law.

The Court first ventured that the equal protection clause would demand special scrutiny of discriminations that affected fundamental rights or interests. In Skinner v. Oklahoma[case]Skinner v. Oklahoma[Skinner v. Oklahoma] (1942), the Court held that a law that provided for compulsory sterilizationCompulsory sterilization of certain habitual criminals but not others discriminated with respect to the fundamental right of procreation. In such cases, the Court determined, it would strictly scrutinize the asserted justifications for the discrimination. Finding such justification lacking in Skinner, the Court ruled that the sterilization law violated the Fourteenth Amendment’s equal protection clause. In the years following Skinner, the Court determined that matters such as the right to vote, the right to privacy (concerning one’s choice to use contraceptives), the right to travel, and the right to access to justice were sufficiently fundamental to subject acts of discrimination affecting these rights to more rigorous scrutiny.

As the Court was striving to identify particular rights or interests worthy of protection from discriminatory treatment, it also began to study whether particular grounds for discriminating among individuals might be subjected to corresponding rigorous review. For example, the equal protection clause clearly had its genesis in suspicion of laws that classified individuals on the basis of their race. In Korematsu v. United States[case]Korematsu v. United States[Korematsu v. United States] (1944), the Court, in an opinion by Justice Hugo L. Black, codified this suspicion against racial classifications in principle, though the Court approved an act of racial discrimination that relocated people of JapaneseWorld War II;Japanese American relocationJapanese American relocation ancestry to internment camps during World War II. At the level of principle, the Court was adamant: Racial classifications called for the most stringent review. In the application of this principle, though, the Court deferred to the military’s judgment that the prevention of a West Coast invasion required the relocation of people of Japanese ancestry. This holding would be the last in which the Court upheld a law burdening a minority on account of race.Japanese American relocation


Desegregation. After the Court gave a constitutional harbor to racial segregation through its adoption of the separate but equal doctrine, segregation in public schools and a variety of other public and private contexts became deeply entrenched in the South. In Brown v. Board of Education[case]Brown v. Board of Education[Brown v. Board of Education] (1954), however, the Court repudiated the separate but equal doctrine and held that segregated public schools were inherently unequal. The following year, in Brown v. Board of Education II (1955), the Court ruled that desegregation efforts were to proceed “with all deliberate speed.” However, the only haste exhibited with respect to desegregation by southern school districts was directed at eluding the Court’s desegregation order. By 1964, ten years after the decision in Brown, only 2 percent of the schools segregated at the time of the decision had experienced any significant desegregation. The Court, in the meantime, summarily ruled that segregation in golf courses, state parks, beaches, and public transportation violated the equal protection guarantee.

In the 1960’s and 1970’s the Court presided over cases involving efforts of segregated school districts to frustrate desegregation efforts and of federal district courts to further them. In Green v. County School Board of New Kent County[case]Green v. County School Board of New Kent County[Green v. County School Board of New Kent County] (1968), the Court made it clear that desegregation required not simply that school districts cease their previous segregation practices but that they dismantle the segregated school systems produced by those practices. Eventually, the Court approved radical strategies to secure desegregation. Most controversially, in Swann v. Charlotte-Mecklenburg Board of Education[case]Swann v. Charlotte-Mecklenburg Board of Education[Swann v. Charlotte-Mecklenburg Board of Education] (1971), the Court upheld a district court order requiring widespread busing of students to create racially balanced schools.School integration and busing Importantly, though, the Court held that such remedies required a showing that a school district had engaged in illegal segregation practices de jure segregation, or segregation by law. The existence in schools of segregation that could be traced to social practices rather than officially sanctioned practices de facto segregation was not sufficient to justify a federal court to order remedies such as busing.

Suspect and Quasi-Suspect Classifications

In the years that followed the Court’s decisions in Korematsu and Brown, the Court ventured to determine whether other ways of classifying individuals should be treated with a constitutional suspicion comparable to that now applied to racial discrimination. Classification schemes treated to this kind of suspicion are referred to as “suspect classifications,”Suspect classifications and are presumptively invalid except in those cases in which the government demonstrates that the classification is necessary to achieve some compelling government interest. In its inquiry into whether other forms of classifications were suspect, the Court was guided by one of constitutional law’s most famous footnotes: footnote 4 from the opinion of Justice Harlan Fiske StoneStone, Harlan Fiske in United States v. Carolene Products Co.[case]Carolene Products Co., United States v.[Carolene Products Co., United States v.] (1938). In an otherwise unremarkable decision, Justice Stone suggested for the Court that heightened scrutiny might be justified for laws reflecting prejudice against “discrete and insular minorities.” In practice, the Court has identified race, religion, and national or ethnic origin as suspect classifications. Additionally, laws discriminating among individuals on the basis of whether they are U.S. citizens are suspect, except in a narrow range of cases involving citizenship requirements for voting or for holding positions closely related to democratic self-government.

The Court wrestled at length over the question of whether laws that classified individuals on the basis of their gender should receive the strict scrutiny applied to suspect classifications. DiscriminationDiscrimination, sex on the basis of gender classifies individuals according to an immutable characteristic, and the Court has often expressed its suspicion of using immutable traits as grounds for distinguishing among individuals. Nevertheless, whether men or women receive less favorable treatment under a particular gender classification, neither group can readily be identified as a discrete and insular minority. Accordingly, the Court eventually fashioned an intermediate level of scrutiny for gender classifications, more rigorous than the scrutiny applied to normal legislative classifications but not so rigorous as that applied to suspect classifications such as laws discriminating on the basis of race. Classification schemes subjected to this intermediate scrutiny are sometimes referred to as “quasi-suspect classifications.” The Court included within this category both laws that discriminate on the basis of gender and those that discriminate on the basis of illegitimacy. The Court will uphold these kinds of laws only if they are supported by some important government purpose and the discrimination at issue is substantially related to achieving this important purpose.

Other Classifications

The Court turned away a variety of other claims that particular forms of classifying individuals should be treated as suspect or quasi-suspect. For example, except in cases involving access to certain aspects of justice, the Court declined to treat with any special suspicion laws that classify individuals on the basis of wealth. Furthermore, the Court refused to recognize classifications on the basis of age as inherently suspect, leaving the protection of individuals from age discrimination to the political process.

Nevertheless, the Court did not automatically sustain classification schemes when they were neither suspect nor quasi-suspect. For a classification that is neither suspect nor quasi-suspect, the Court applies what it refers to as rational basis scrutiny. In these circumstances, classifications are upheld as long as they are rationally related to a legitimate government interest. Although the application of this standard of review normally upholds a government classification scheme, occasionally it does not. For example, in Cleburne v. Cleburne Living Center[case]Cleburne v. Cleburne Living Center[Cleburne v. Cleburne Living Center] (1985), the Court declined to classify mental infirmity as a suspect or quasi-suspect category. Nevertheless, it declared unconstitutional a zoning ordinance that required a special permit for the operation of a group home for the mentally retarded on a particular site, even though the ordinance allowed a wide variety of other land uses on the site. The Court concluded that the negative reactions of nearby residents and the unsubstantiated fears of elderly residents concerning the mental retardation home were not legitimate justifications for discriminatory treatment of the home. Similarly, in Romer v. Evans[case]Romer v. Evans[Romer v. Evans] (1996), the Court invalidated a Colorado constitutional amendment that discriminated against homosexuals by providing that no state or municipal law could accord them any special protection from discrimination. Although the Court did not determine that sexual orientation was a suspect or quasi-suspect classification, a majority of the justices reasoned that the amendment reflected “bare animus” against gays and lesbians, and that this animus was not a legitimate basis for upholding the amendment from an equal protection challenge.

Affirmative Action

Affirmative Action In his well-known dissent to the opinion of the Court in Plessy v. Ferguson (1896), Justice John Marshall HarlanHarlan, John Marshall rejected the separate but equal doctrine embraced by the majority. Instead, in his view the equal protection clause mandated that the law be color-blind. Understood literally, this color-blind reading of the equal protection clause would prevent laws designed to benefit racial minorities as well as those designed to burden and harass them. Beginning in the 1960’s and 1970’s, though, many American observers contended that the legacy of past and continuing racial discrimination in the United States could not be rectified with taking affirmative steps. These affirmative actions typically consisted of laws and policies that singled out racial minorities for beneficial or even preferential treatment as a way of remedying past discriminatory laws and policies.

Beginning with the Court’s decision in Korematsu, it was clear that laws intentionally burdening racial minorities would be subjected to strict scrutiny. More than forty years would pass before the Court finally concluded that laws the singled out racial minorities for beneficial treatment would also receive the same rigorous scrutiny. The path to this ultimate conclusion was neither direct nor widely supported. In its first important consideration of affirmative action plans, a majority of the Court concluded in Regents of the University of California v. Bakke[case]Regents of the University of California v. Bakke[Regents of the University of California v. Bakke] (1978) that the equal protection clause prevented a state university from using racial quotas in its admissions process but permitted the university to consider race as one factor in striving to create a diverse student body. Therefore, while the university could not set aside a particular number of seats for minority students, it could treat minority status as one among several favorable factors in the admissions process. A few years later, in Fullilove v. Klutznick[case]Fullilove v. Klutznick[Fullilove v. Klutznick] (1980), the Court upheld a challenge against a federal set-aside program that gave certain preferences to minority businesses in the award of federal contracts. In neither Bakke nor Fullilove did the Court determine the standard of review to be applied in affirmative action cases.

The final years of the twentieth century witnessed a conservative majority on the Court becoming increasingly hostile to affirmative action programs. In closely divided decisions, the Court eventually determined, first in Richmond v. J. A. Croson Co.[case]Richmond v. J. A. Croson Co.[Richmond v. J. A. Croson Co.] (1989) and then in Adarand Constructors v. Peña[case]Adarand Constructors v. Peña[Adarand Constructors v. Pena] (1995), that equal protection principles required that all racial classifications, including those intended to benefit racial minorities, be subjected to strict scrutiny. Though at least some forms of affirmative action might be justified as necessary to serve compelling governmental interests such as remedying past racial discrimination, it nevertheless appeared that many affirmative action programs would no longer survive challenge under equal protection.

Further Reading
  • An excellent introduction to this subject is Francis Graham Lee’s Equal Protection: Rights and Liberties Under the Law (Santa Barbara, Calif.: ABC-Clio, 2003). A general treatment of the equal protection clause can be found in Darien A. McWhirter’s Equal Protection: Exploring the Constitution (Phoenix, Ariz.: Oryx Press, 1995). For historical coverage of the idea of equality in U.S. history, see J. R. Pole’s Pursuit of Equality in American History (2d ed., Berkeley: University of California Press, 1993) and Charles Redenius’s The American Ideal of Equality: From Jefferson’s Declaration to the Burger Court (Port Washington, N.Y.: Kennikat Press, 1981). The Fourteenth Amendment: From Political Principle to Judicial Doctrine by William E. Nelson (Cambridge, Mass.: Harvard University Press, 1988) provides a useful analysis of the broader context of the equal protection clause in the Fourteenth Amendment. The Civil Rights Era: Origins and Development of National Policy, 1960-1972, by Hugh Davis Graham (New York: Oxford University Press, 1990), examines a crucial period in the enforcement of the equal protection guarantee through civil rights laws. Particular treatments relating to racial equality include African Americans and the Living Constitution, edited by John Hope Franklin and Genna Rae McNeil (Washington, D.C.: Smithsonian Institution Press, 1995), and Simple Justice: The History of “Brown v. Board of Education” and Black America’s Struggle for Equality, by Richard Kluger (New York: Alfred A. Knopf, 1976). Useful sources for further reading concerning gender discrimination issues are Cathy Young’s Ceasefire! Why Women and Men Must Join Forces to Achieve True Equality (New York: Free Press, 1999), and Robert Max Jackson’s Destined for Equality: The Inevitable Rise of Women’s Status (Cambridge, Mass.: Harvard University Press, 1998). For treatments of the controversy regarding affirmative action, one may consult Affirmative Discrimination: Ethnic Inequality and Public Policy by Nathan Glazer (New York: Basic Books, 1975), A Conflict of Rights: The Supreme Court and Affirmative Action by Melvin I. Urofsky (New York: Scribner’s Sons, 1991), and The Color-Blind Constitution, by Andrew Kull (Cambridge, Mass.: Harvard University Press, 1992).

Affirmative action

Age discrimination

Civil Rights Acts

Civil Rights movement


Fourteenth Amendment

Fundamental rights

Judicial scrutiny

Race and discrimination

Separate but equal doctrine

Suspect classifications

Categories: History