Justice WHITE delivered the opinion of the Court.
A Texas city denied a special use permit for the operation of a group home for the mentally retarded, acting pursuant to a municipal zoning ordinance requiring permits for such homes. The Court of Appeals for the Fifth Circuit held that mental retardation is a "quasi-suspect" classification and that the ordinance violated the Equal Protection Clause because it did not substantially further an important governmental purpose. We hold that a lesser standard of scrutiny is appropriate, but conclude that under that standard the ordinance is invalid as applied in this case.
In July 1980, respondent Jan Hannah purchased a building at 201 Featherston Street in the city of Cleburne, Texas, with the intention of leasing it to Cleburne Living Center, Inc. (CLC), for the operation of a group home for the mentally retarded. . . .
The city informed CLC that a special use permit would be required for the operation of a group home at the site, and CLC accordingly submitted a permit application. In response to a subsequent inquiry from CLC, the city explained that under the zoning regulations applicable to the site, a special use permit, renewable annually, was required for the construction of "[h]ospitals for the insane or feeble-minded, or alcoholic [sic] or drug addicts, or penal or correctional institutions. . . ." After holding a public hearing on CLC's application, the City Council voted 3 to 1 to deny a special use permit. . . .
The Equal Protection Clause of the Fourteenth Amendment commands that no State shall "deny to any person within its jurisdiction the equal protection of the laws," which is essentially a direction that all persons similarly situated should be treated alike. Section 5 of the Amendment empowers Congress to enforce this mandate, but absent controlling congressional direction, the courts have themselves devised standards for determining the validity of state legislation or other official action that is challenged as denying equal protection. The general rule is that legislation is presumed to be valid and will be sustained if the classification drawn by the statute is rationally related to a legitimate state interest. . . .
The general rule gives way, however, when a statute classifies by race, alienage, or national origin. These factors are so seldom relevant to the achievement of any legitimate state interest that laws grounded in such considerations are deemed to reflect prejudice and antipathy a view that those in the burdened class are not as worthy or deserving as others. For these reasons and because such discrimination is unlikely to be soon rectified by legislative means, these laws are subjected to strict scrutiny and will be sustained only if they are suitably tailored to serve a compelling state interest.
Legislative classifications based on gender also call for a heightened standard of review. That factor generally provides no sensible ground for differential treatment. . . . A gender classification fails unless it is substantially related to a sufficiently important governmental interest. . . .
We have declined, however, to extend heightened review to differential treatment based on age. . .
Against this background, we conclude for several reasons that the Court of Appeals erred in holding mental retardation a quasi-suspect classification calling for a more exacting standard of judicial review than is normally accorded economic and social legislation. First, it is undeniable, and it is not argued otherwise here, that those who are mentally retarded have a reduced ability to cope with and function in the everyday world. Nor are they all cut from the same pattern: as the testimony in this record indicates, they range from those whose disability is not immediately evident to those who must be constantly cared for. They are thus different, immutably so, in relevant respects, and the States' interest in dealing with and providing for them is plainly a legitimate one. How this large and diversified group is to be treated under the law is a difficult and often a technical matter, very much a task for legislators guided by qualified professionals and not by the perhaps ill-informed opinions of the judiciary. Heightened scrutiny inevitably involves substantive judgments about legislative decisions, and we doubt that the predicate for such judicial oversight is present where the classification deals with mental retardation.
Second, the distinctive legislative response, both national and state, to the plight of those who are mentally retarded demonstrates not only that they have unique problems, but also that the lawmakers have been addressing their difficulties in a manner that belies a continuing antipathy or prejudice and a corresponding need for more intrusive oversight by the judiciary. . . .
Third, the legislative response, which could hardly have occurred and survived without public support, negates any claim that the mentally retarded are politically powerless in the sense that they have no ability to attract the attention of the lawmakers. Any minority can be said to be powerless to assert direct control over the legislature, but if that were a criterion for higher level scrutiny by the courts, much economic and social legislation would now be suspect. . . .
Fourth, if the large and amorphous class of the mentally retarded were deemed quasi-suspect for the reasons given by the Court of Appeals, it would be difficult to find a principled way to distinguish a variety of other groups who have perhaps immutable disabilities setting them off from others, who cannot themselves mandate the desired legislative responses, and who can claim some degree of prejudice from at least part of the public at large. One need mention in this respect only the aging, the disabled, the mentally ill, and the infirm. We are reluctant to set out on that course, and we decline to do so. . . .
Our refusal to recognize the retarded as a quasi-suspect class does not leave them entirely unprotected from invidious discrimination. To withstand equal protection review, legislation that distinguishes between the mentally retarded and others must be rationally related to a legitimate governmental purpose. . . .
The short of it is that requiring the permit in this case appears to us to rest on an irrational prejudice against the mentally retarded. . . .
The judgment of the Court of Appeals is affirmed insofar as it invalidates the zoning ordinance. . . .
Justice MARSHALL, with whom Justice BRENNAN and Justice BLACKMUN join, concurring in part and dissenting in part.
. . . The Court holds the ordinance invalid on rational-basis grounds and disclaims that anything special, in the form of heightened scrutiny, is taking place. Yet Cleburne's ordinance surely would be valid under the traditional rational-basis test applicable to economic and commercial regulation. In my view, it is important to articulate, as the Court does not, the facts and principles that justify subjecting this zoning ordinance to the searching review the heightened scrutiny that actually leads to its invalidation. . . .
. . . [T]he Court's heightened-scrutiny discussion is . . . puzzling given that Cleburne's ordinance is invalidated only after being subjected to precisely the sort of probing inquiry associated with heightened scrutiny. To be sure, the Court does not label its handiwork heightened scrutiny, and perhaps the method employed must hereafter be called "second order" rational-basis review rather than "heightened scrutiny." But however labeled, the rational-basis test invoked today is most assuredly not the rational-basis test of Williamson v. Lee Optical of Oklahoma, Inc., 348 U.S. 483 (1955). . . .
The refusal to acknowledge that something more than minimum rationality review is at work here is, in my view, unfortunate in at least two respects. The suggestion that the traditional rational-basis test allows this sort of searching inquiry creates precedent for this Court and lower courts to subject economic and commercial classifications to similar and searching "ordinary" rational-basis review a small and regrettable step back toward the days of Lochner v. New York, 198 U.S. 45 (1905). Moreover, by failing to articulate the factors that justify today's "second order" rational-basis review, the Court provides no principled foundation for determining when more searching inquiry is to be invoked. Lower courts are thus left in the dark on this important question, and this Court remains unaccountable for its decisions employing, or refusing to employ, particularly searching scrutiny. Candor requires me to acknowledge the particular factors that justify invalidating Cleburne's zoning ordinance under the careful scrutiny it today receives. . . .