Meaning of equal protection
The Equal Protection Clause, found in the 14th Amendment, requires the government to treat all individuals equally under the law. It prohibits discrimination based on certain protected characteristics and ensures that laws are applied uniformly to people in similar circumstances.
While the 14th Amendment technically applies only to state governments, the Supreme Court has held (through Bolling v. Sharpe, 1954) that the 5th Amendment's Due Process Clause imposes the same equal protection requirements on the federal government. So in practice, equal protection binds every level of government.
Levels of scrutiny
When someone challenges a law as violating equal protection, courts don't just ask "is this fair?" They apply a specific level of scrutiny based on what kind of classification the law uses or what right it affects. The level of scrutiny determines how hard the government has to work to justify the law, and who carries the burden of proof.
Strict scrutiny
This is the highest and most demanding standard. It applies to classifications based on race, national origin, or laws that infringe on fundamental rights.
To survive strict scrutiny, the government must show:
- The law serves a compelling state interest (not just a good reason, but an extremely important one).
- The law is narrowly tailored, meaning it's the least restrictive way to achieve that interest.
There's a presumption of unconstitutionality here. The government bears the burden of proof, and most laws subjected to strict scrutiny are struck down.
Intermediate scrutiny
This middle-tier standard applies to classifications based on gender or illegitimacy (discrimination against children born outside of marriage).
To survive intermediate scrutiny, the government must show:
- The law serves an important governmental interest (a step below "compelling").
- The law is substantially related to achieving that interest.
This requires a tighter fit between the law and its goal than rational basis review, but it's not as demanding as strict scrutiny. The justification must be genuine, not based on stereotypes.
Rational basis review
This is the lowest and most deferential standard. It applies to most economic and social legislation, including classifications based on age or wealth.
To survive rational basis review, the government must show:
- The law is rationally related to a legitimate governmental interest.
The burden flips here: the challenger must prove the law has no rational connection to any conceivable legitimate purpose. Laws almost always survive this standard.
Suspect classifications
Certain classifications are labeled "suspect" because they target groups with a history of discrimination. These classifications automatically trigger heightened scrutiny.
Race and national origin
Race and national origin are the classic suspect classifications, subject to strict scrutiny. The long history of racial discrimination in the U.S. is the reason courts treat these classifications as inherently suspect.
Key examples include laws mandating racial segregation and the internment of Japanese Americans during World War II (upheld at the time in Korematsu v. United States, 1944, but widely condemned since and formally repudiated by the Court in Trump v. Hawaii, 2018).
Alienage
Classifications based on alienage (citizenship status) are generally subject to strict scrutiny. However, there's an important exception: when the government restricts noncitizens from participating in core governmental functions like voting, serving on juries, or holding certain public offices, courts apply the more lenient rational basis review.
Other suspect classes
The Supreme Court has not recognized any additional suspect classes beyond race, national origin, and alienage. There is ongoing debate about whether characteristics like sexual orientation or poverty should receive suspect-class status and trigger heightened scrutiny, but the Court has not taken that step.
Fundamental rights
Equal protection doesn't only protect against discrimination based on who you are. It also protects against laws that burden fundamental rights. When a law restricts a fundamental right unequally, strict scrutiny applies.
Right to vote
Voting is a fundamental right. Laws that restrict or place unequal burdens on the right to vote trigger strict scrutiny. Historical examples include poll taxes (banned by the 24th Amendment and Harper v. Virginia, 1966) and literacy tests, both of which were used to disenfranchise minority voters.
Access to justice
Laws that restrict access to courts can violate equal protection when they disproportionately burden certain groups. For instance, the Court struck down excessive court fees that effectively barred indigent defendants from appealing criminal convictions (Griffin v. Illinois, 1956).
Right to travel
The right to travel between states is a fundamental right. Laws that burden interstate travel, such as lengthy residency requirements before someone can receive public benefits, are subject to strict scrutiny (Shapiro v. Thompson, 1969).
Other fundamental rights
Other rights recognized as fundamental in the equal protection context include the right to privacy, the right to marry, and the right to procreate. Laws that unequally burden any of these rights face strict scrutiny.
Discriminatory intent vs. impact
This distinction trips up a lot of students. There are two ways a law can be discriminatory:
- Discriminatory intent means the government purposely designed the law to discriminate against a protected group.
- Discriminatory impact means a facially neutral law (one that doesn't mention race, gender, etc.) ends up disproportionately harming a protected group in practice.
The critical rule: under the Equal Protection Clause, discriminatory impact alone is generally not enough to prove a violation. The challenger typically must show discriminatory intent. The Court established this principle in Washington v. Davis (1976), holding that a police entrance exam with racially disparate results did not violate equal protection absent proof of discriminatory purpose.
That said, if the impact is so stark and unexplainable by other factors, courts may infer discriminatory intent from the pattern itself (Yick Wo v. Hopkins, 1886).
Affirmative action
Affirmative action refers to policies that give preferences to underrepresented groups to promote diversity or remedy past discrimination. Because race-based affirmative action uses a suspect classification, it triggers strict scrutiny.
Diversity as a compelling interest
For decades, the Supreme Court recognized diversity in higher education as a compelling interest that could justify race-conscious admissions. In Grutter v. Bollinger (2003), the Court upheld a law school admissions program that considered race as one factor in a holistic review.
However, in Students for Fair Admissions v. Harvard (2023), the Court effectively ended race-conscious admissions in higher education, holding that Harvard's and UNC's programs violated equal protection. This is a major recent development that significantly changed the legal landscape of affirmative action.
Narrowly tailored programs
Even before the 2023 ruling, affirmative action programs had to be narrowly tailored. Courts considered factors like:
- Whether the program was flexible and individualized
- Whether race-neutral alternatives had been considered
- The burden placed on non-beneficiaries
- Whether the program had a logical endpoint
Quotas and rigid numerical targets were always unconstitutional (established in Regents of the University of California v. Bakke, 1978). Only flexible, individualized approaches had any chance of surviving strict scrutiny.
Gender discrimination
Gender classifications receive intermediate scrutiny. The government must show that a gender-based law is substantially related to an important governmental interest, and the justification must be genuine.
The landmark case here is United States v. Virginia (1996), where the Court struck down the Virginia Military Institute's male-only admissions policy. Justice Ginsburg's opinion emphasized that the government cannot rely on overbroad generalizations about men's and women's abilities or preferences.
Examples of gender-based laws that courts have evaluated include different military draft registration requirements for men and women, and statutory rape laws that apply differently based on sex.
Discrimination based on age
Age is not a suspect classification. Laws that classify based on age receive only rational basis review, which means they're upheld as long as they're rationally related to a legitimate interest.
Examples include mandatory retirement ages for certain professions and minimum age requirements for activities like driving or voting. Congress has addressed age discrimination through statutes like the Age Discrimination in Employment Act (ADEA), but that's a statutory protection, not a constitutional one under equal protection.
Discrimination against the poor
Poverty is also not a suspect classification, so wealth-based distinctions generally receive rational basis review. However, the Court has been more protective when poverty intersects with fundamental rights.
For example, the Court struck down poll taxes (Harper v. Virginia, 1966) because they conditioned the fundamental right to vote on wealth. Similarly, the Court has required states to provide access to courts for indigent criminal defendants regardless of ability to pay. The pattern: poverty alone won't trigger heightened scrutiny, but poverty combined with a fundamental right can lead to stricter review.
Same-sex marriage and equal protection
In Obergefell v. Hodges (2015), the Supreme Court held that state laws banning same-sex marriage violated both the Due Process Clause and the Equal Protection Clause of the 14th Amendment. The Court found that the right to marry is fundamental and that there was no sufficient justification for excluding same-sex couples.
The Court did not clearly specify which level of scrutiny it was applying, which has left some ambiguity. It relied heavily on the connection between liberty (due process) and equality (equal protection), treating them as reinforcing principles rather than picking a single tier of scrutiny.
Equal protection in education
Equal protection has driven some of the most significant changes in American education.
School desegregation
Brown v. Board of Education (1954) is one of the most important Supreme Court decisions in U.S. history. The Court unanimously held that racial segregation in public schools violates equal protection, overturning the "separate but equal" doctrine from Plessy v. Ferguson (1896). Chief Justice Warren wrote that separating children solely because of race "generates a feeling of inferiority" that may affect their hearts and minds in ways unlikely to ever be undone.
The follow-up case, Brown II (1955), ordered desegregation to proceed "with all deliberate speed," though actual implementation took years and often required federal enforcement.
Funding disparities
Challenges to unequal school funding between wealthy and poor districts have had mixed results at the federal level. In San Antonio Independent School District v. Rodriguez (1973), the Supreme Court held that education is not a fundamental right under the federal Constitution and that wealth is not a suspect classification. The funding scheme survived rational basis review.
However, many state courts have struck down unequal funding systems under their own state constitutions, which sometimes provide stronger equal protection guarantees than the federal Constitution.
Congressional enforcement of equal protection
Section 5 of the 14th Amendment gives Congress the power to enforce equal protection through legislation. Major laws passed under this authority include:
- The Civil Rights Act of 1964, which prohibits discrimination in employment, public accommodations, and federally funded programs
- The Voting Rights Act of 1965, which targeted racial discrimination in voting
Congress's enforcement power is not unlimited, though. In City of Boerne v. Flores (1997), the Supreme Court held that Section 5 legislation must be "congruent and proportional" to identified constitutional violations. Congress can remedy and prevent discrimination, but it cannot redefine what the Constitution means. This principle has led the Court to strike down parts of congressional enforcement legislation that it viewed as overreaching.