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Equal Protection of the Law


EQUAL PROTECTION OF THE LAW refers to the constitutional concept that the government should treat similar persons similarly and should not treat people of different circumstances as if they were the same. An equality principle appeared in the Declaration of Independence ("We hold these truths to be self evident: that all men are created equal …") but did not appear in the Constitution itself until the passage of the Fourteenth Amendment in 1868. The amendment embodied the commitment of the victorious Northern states to afford some measure of national constitutional protection for the rights of the newly emancipated slaves. The amendment's framers deliberately worded the equal protection clause more broadly, however, declaring, "No state shall … deny to any person within its jurisdiction the equal protection of the laws." In part because of its breadth and elasticity, this provision has become probably the single most important source of constitutional protection for individual rights.

Though the terms of the equal protection clause apply only to state and local governments, the Supreme Court has held the federal government to almost identical requirements. In Bolling v. Sharpe, 347 U.S. 497 (1954), the Supreme Court explained that a guarantee of equal protection was implicit in the due process clause of the Fifth Amendment, which applies to the federal government.

Problems Addressed by the Equal Protection Clause

The issue of equal protection arises when the government classifies individuals under the terms of some statute or regulation, or when government actors purposefully treat individuals differently in applying statutes that are ostensibly neutral. The analytical difficulty springs from the fact that the need for classification and different treatment is inherent in the nature of governmental activity. Even in the most benign situations, the government in pursuing social goals must "draw lines" to identify who is required to perform a particular action or who will receive a government benefit. The equal protection guarantee ensures not the absence of these classifications but the absence of impermissible criteria, such as race, in their creation or application—unless the government can show adequate justification for the criteria. The equal protection concept also protects certain "fundamental interests," such as the right to vote, from government classifications that burden those interests.

Whether specific persons are properly placed within a classification is not a matter for equal protection jurisprudence. Equal protection addresses the legitimacy of the classification itself, whether it is inherent in the law or arises during the law's application. It is the Constitution's guarantee of procedural due process that protects individuals from wrongful classification by ensuring some level of fair process in determining whether the classification is properly applied in a specific instance.

Methods of Equal Protection Analysis

Under equal protection analysis, the question of whether a law is proper turns on the legitimacy of the ends desired, the nature of the classification itself, and the "fit" between the ends and the way government has classified persons in light of that end. Traditionally, courts have described their analysis in terms of levels of scrutiny: "strict" scrutiny for particularly "suspect" classifications such as race; "intermediate" scrutiny for classifications, such as those based on sex, that require heightened attention but do not raise the exceptional problems of those in the "strict" category; and "rational basis" scrutiny for all other classifications. Some members of the Court, most notably Justice Thurgood Marshall, have periodically urged the Court to abandon these categories, and many commentators agree that a more flexible approach would allow the Court to be more sensitive to the complexities these cases present. With some exceptions, however, the Court continues to adhere to these general categories.

Strict Scrutiny. To satisfy strict scrutiny, a law must serve an extremely important, "compelling" interest. Also, the fit between the interest and classification must be very close. That is, the classification must be "narrowly tailored" to serve the goal of the law. The application of strict scrutiny is almost always fatal to the law in question.

Courts use strict scrutiny to evaluate classifications based on race, national origin, and—sometimes—status as an alien. There is much debate about why these categories should require strict scrutiny. In the famous "Footnote 4" of United States v. Carolene Products Co., 304 U.S. 144 (1938), the Court explained that strict scrutiny is called for because "prejudice against discrete and insular minorities may be a special condition, which tends seriously to curtail the operation of those political processes ordinarily to be relied upon to protect minorities." Racial classifications are considered so problematic that courts apply strict scrutiny even when the classifications are intended to benefit racial minorities, such as in affirmative action programs (Adarand Constructors, Inc. v. Pena, 515 U.S. 200, 1995), and even when the racial classification may in fact correlate with attributes relevant to legitimate government objectives. The most famous equal protection case in the context of race is Brown v. Board of Education, 347 U.S. 483 (1954), which held racial segregation in public schools to be unconstitutional.

The Supreme Court has also applied strict scrutiny to laws that classify people in some way that burdens the exercise of a fundamental right, such as voting. In Reynolds v. Sims, 377 U.S. 533 (1964), the Supreme Court used the equal protection guarantee as the basis for the creation of the principle of "one person, one vote." While not explicitly invoking strict scrutiny, the Court in Bush v. Gore, 531 U.S. 98 (2000), stopped a manual recount of ballots in the contested presidential election in Florida, holding that inconsistent standards for deciding which ballots should be counted violated equal protection.

Intermediate Scrutiny. Under intermediate scrutiny, courts will not uphold a governmental classification unless it has a "substantial relationship" to an "important" government interest. While the doctrinal formulations have varied, both the "means" and the "ends" tests are less exacting than strict scrutiny and more demanding than rationality review. The Supreme Court has used intermediate scrutiny in cases involving classifications based on sex and the extramarital status of children, and sometimes in cases involving aliens.

The Court adopted the intermediate level of review for gender classifications in the case of Craig v. Boren, 429 U.S. 190 (1976), in which the Court struck down a statute that allowed women over age eighteen to purchase beer but allowed males to purchase beer only after age twenty-one. Applying intermediate scrutiny, the Court has invalidated gender segregation in state nursing schools (Mississippi University for Woman v. Hogan, 458 U.S. 718, 1982), single-sex state universities (United States v. Virginia, 518 U.S. 515, 1996), statutory provisions offering lower benefits to families of working women than to families of working men (Frontiero v. Richardson, 411 U.S. 677, 1973), and social security regulations that provided smaller survivor benefits to widowers than to widows (Califano v. Goldfarb, 430 U.S. 199, 1977). On the other hand, the Court has upheld a requirement that only men register for the draft (Rostker v. Goldberg, 453 U.S. 57, 1981) and a statutory rape law that punished only adult men for having sex with an underage individual of the opposite sex (Michael M. v. Superior Court, 450 U.S. 464, 1981).

Rationality Review. A classification that does not burden fundamental interests and that is not drawn on a suspect basis is subject only to low-level "rationality" review by the Court. The Court will uphold the law in question as long as the classification is a rational method of accomplishing a legitimate government interest. In Williamson v. Lee Optical of Oklahoma, 348 U.S. 483 (1955), the Court made clear that rationality review would sustain legislative classifications even if the basis for such classification was not obvious and even if the means-ends fit was loose. The legislature can address the problem "one step at a time" or even select one aspect of a problem and "apply a remedy there, neglecting the others."

Courts apply rational basis scrutiny to the majority of legislative enactments, including those concerning economic regulation, welfare benefits, property use, business activity, and individual conduct. Also, the Court decided in Washington v. Davis, 426 U.S. 229 (1976), that classifications not written in racial terms or intended to further a discriminatory purpose would be subject to rationality review even if the law in practice imposed a disparate impact on racial minorities. The Court thus upheld a qualifying test for government job applicants, even though more African American applicants failed the test than white applicants and even though the test had not been shown to provide a reliable measure of future job performance.

While rational basis review almost always results in classification being upheld, the Court in isolated situations has invalidated laws while purporting to apply rationality review. In City of Cleburne v. Cleburne Living Center, 473 U.S. 432 (1985), the Court used rationality review to invalidate a city's zoning ordinance that prevented the construction of a group home for the mentally retarded. Even though the Court expressly refused to declare mental retardation a suspect classification, the Court struck down the statute as based on "irrational" prejudice. The Court used a similar justification in Romer v. Evans, 517 U.S. 620 (1996), to invalidate an amendment to the Colorado state constitution that repealed all local ordinances banning discrimination on the basis of sexual orientation and that prohibited all state or local governmental action designed to protect homosexual persons from discrimination. The Court held that the amendment imposed special disabilities on homosexuals, that these disabilities were animated by "animosity" toward a class of people, and that animosity cannot itself be a "legitimate governmental interest."


Bender, Leslie, and Daan Braveman. Power, Privilege, and Law: A Civil Rights Reader. St. Paul, Minn.: West, 1995. Anthology of readings.

Ely, John Hart. Democracy and Distrust: A Theory of Judicial Review. Cambridge, Mass.: Harvard University Press, 1980. Famous theoretical treatment of equal protection guarantee.

Garvey, John H., and T. Alexander Aleinikoff. Modern Constitutional Theory: A Reader. 4thed. St. Paul, Minn.: West, 1999. Anthology of readings. See pp. 472–665.

Rotunda, Ronald D., and John E. Nowak. Treatise on Constitutional Law: Substance and Procedure. 3d ed. St. Paul, Minn.: West, 1999. Comprehensive treatise. See vol. 3, pp. 202–826.

Stone, Geoffrey R., et al. Constitutional Law. 4thed. New York: Aspen, 2001. Preeminent constitutional law casebook.


See alsoBrown v. Board of Education of Topeka ; Bush v. Gore ; Constitution of the United States ; Craig v. Boren ; Declaration of Independence ; Due Process of Law ; Frontiero v. Richardson ; Romer v. Evans (1996) ; United States v. Virginia ; Williamson v. Lee Optical ; andvol. 9:Congress Debates the Fourteenth Amendment .

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