Constitutional Law Fundamentals

'The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.' For most of the twentieth century, the Tenth Amendment was treated as a tautology — a reminder rather than a constraint. The Rehnquist Court revived it as a substantive limit in cases like New York v. United States (1992) and Printz v. United States (1997), which together established the 'anti-commandeering' rule: the federal government cannot compel state legislatures or executive officers to enforce federal law.

Article I, Section 8, Clause 3 lets Congress 'regulate Commerce... among the several States.' Gibbons v. Ogden (1824) read 'commerce' broadly. Wickard v. Filburn (1942) reached its high-water mark, holding that a farmer's homegrown wheat, consumed on his own farm, could be regulated because in aggregate such activity affected interstate commerce. United States v. Lopez (1995) was the first Commerce Clause decision in nearly sixty years to invalidate a federal statute, striking the Gun-Free School Zones Act. Lopez and Morrison (2000) require that the regulated activity be economic in nature.

Clause 18 of Article I, Section 8 lets Congress 'make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers.' In McCulloch v. Maryland (1819) Chief Justice Marshall read 'necessary' as 'convenient or useful,' not 'indispensable,' giving Congress wide latitude to choose the means of executing enumerated powers. United States v. Comstock (2010) reaffirmed the test: there must be a means-ends rationality between the statute and an enumerated power.

Article VI makes federal law 'the supreme Law of the Land.' When state and federal law conflict, federal law wins. Pre-emption comes in three flavors: express (the statute says so), field (federal regulation is so pervasive it occupies the field, as with immigration in Arizona v. United States 2012), and conflict (compliance with both is impossible, or state law stands as an obstacle to federal purposes). Pre-emption disputes drive a huge share of modern litigation in immigration, drug pricing, employment, and energy.

Chief Justice Roberts held that the ACA's individual mandate exceeded the Commerce Clause — Congress cannot compel commerce, only regulate existing commerce — but that the mandate was a valid exercise of the taxing power because the penalty functioned as a tax. A separate seven-justice coalition held that the ACA's Medicaid expansion, by threatening states with loss of all existing Medicaid funds, was unconstitutionally coercive: 'a gun to the head.' NFIB is the modern touchstone for both Commerce Clause and Spending Clause limits.

Chief Justice Marshall held that the Judiciary Act of 1789 unconstitutionally expanded the Supreme Court's original jurisdiction, and that 'it is emphatically the province and duty of the judicial department to say what the law is.' Marbury established that federal courts have the power and duty to invalidate statutes that conflict with the Constitution. The decision was politically shrewd: Marshall denied himself jurisdiction while announcing a power that would dwarf any individual ruling.

Article III limits federal courts to 'Cases' and 'Controversies.' Standing requires (1) a concrete and particularized injury in fact, (2) causation traceable to the defendant, and (3) redressability by the court (Lujan v. Defenders of Wildlife 1992). Ripeness asks whether the dispute is sufficiently developed; mootness asks whether a live controversy still exists. TransUnion v. Ramirez (2021) reaffirmed that statutory injuries must still be 'concrete' to satisfy Article III.

Some constitutional questions are committed to the political branches and are non-justiciable. Baker v. Carr (1962) listed six factors, the two most important being a 'textually demonstrable constitutional commitment' of the issue to another branch, and a 'lack of judicially discoverable and manageable standards.' Rucho v. Common Cause (2019) applied the doctrine to partisan gerrymandering, holding it beyond federal-court competence — though state constitutions and state courts remain in play.

The Fifth Amendment binds the federal government; the Fourteenth, ratified in 1868, binds the states. Both forbid the deprivation of 'life, liberty, or property, without due process of law.' Through the doctrine of selective incorporation (Palko v. Connecticut 1937; Duncan v. Louisiana 1968; McDonald v. Chicago 2010 for the Second Amendment; Timbs v. Indiana 2019 for the Excessive Fines Clause), nearly all Bill of Rights protections now bind the states.

Before depriving a person of a protected interest in life, liberty, or property, the government must provide notice and an opportunity to be heard. The threshold question is whether the interest qualifies — a job, a welfare benefit, or parental rights can all be 'property' or 'liberty' interests (Goldberg v. Kelly 1970 on welfare; Goss v. Lopez 1975 on public-school suspension).

To decide what process is due, courts balance three factors: (1) the private interest at stake, (2) the risk of erroneous deprivation under existing procedures and the probable value of additional safeguards, and (3) the government's interest, including fiscal and administrative burdens. Mathews is the workhorse test for everything from Social Security disability terminations to Guantanamo detainee challenges (Hamdi v. Rumsfeld 2004).

Beyond procedure, the Due Process Clauses protect certain fundamental rights from government interference regardless of process. The modern doctrine traces through Meyer v. Nebraska (1923), Pierce v. Society of Sisters (1925), Griswold v. Connecticut (1965), Roe v. Wade (1973), Lawrence v. Texas (2003), Obergefell v. Hodges (2015), and — going the other direction — Dobbs v. Jackson Women's Health (2022). Washington v. Glucksberg (1997) supplied the dominant test: a right must be 'deeply rooted in this Nation's history and tradition.'

The Fourteenth Amendment forbids any state to 'deny to any person within its jurisdiction the equal protection of the laws.' The Court applies one of three levels of review depending on the classification or the right involved. Bolling v. Sharpe (1954) reverse-incorporated equal protection against the federal government through the Fifth Amendment's Due Process Clause.

Laws that classify by race or national origin, or that burden fundamental rights, are presumptively unconstitutional. The government must show the law is narrowly tailored to a compelling state interest. Loving v. Virginia (1967) struck anti-miscegenation laws; Korematsu (1944) is the rare and now-repudiated case upholding race-based action (Trump v. Hawaii 2018 expressly disavowed it). SFFA v. Harvard (2023) applied strict scrutiny to end race-conscious college admissions.

Classifications by sex must be 'substantially related' to an 'important government interest' (Craig v. Boren 1976). United States v. Virginia (1996) — the VMI case — tightened the standard to require an 'exceedingly persuasive justification.' Classifications based on illegitimacy receive similar review. Bostock v. Clayton County (2020) reached LGBTQ+ employment discrimination through Title VII statutory interpretation rather than equal protection, so the constitutional tier for sexual orientation and gender identity remains unsettled.

All other classifications must merely be 'rationally related' to a 'legitimate' government interest. This is enormously deferential — laws survive even on hypothetical justifications (FCC v. Beach Communications 1993). The exceptions are striking: 'rational basis with bite' cases (Romer v. Evans 1996, USDA v. Moreno 1973, City of Cleburne 1985) struck laws because the only conceivable purpose was 'animus' toward an unpopular group.

The First Amendment commands that 'Congress shall make no law... abridging the freedom of speech.' The default rule is that content-based restrictions are presumptively unconstitutional and trigger strict scrutiny (Reed v. Town of Gilbert 2015). Content-neutral time, place, and manner restrictions get intermediate review. The Court has carved out narrow unprotected categories: incitement (Brandenburg v. Ohio 1969), true threats (Counterman v. Colorado 2023 added a recklessness mens rea), fighting words, obscenity (Miller v. California 1973), and child sexual abuse material.

Lemon v. Kurtzman (1971) supplied a three-part test (secular purpose, primary effect that neither advances nor inhibits religion, no excessive entanglement) that governed Establishment Clause cases for fifty years. In Kennedy v. Bremerton School District (2022), the Court declared Lemon 'long abandoned' and instructed courts to interpret the clause 'by reference to historical practices and understandings.' The new framework looks to founding-era practice, similar to Town of Greece v. Galloway (2014) on legislative prayer.

Employment Division v. Smith (1990) held that neutral, generally applicable laws survive Free Exercise challenge even when they burden religious practice. Congress responded with the Religious Freedom Restoration Act (1993), which restored strict scrutiny for federal laws burdening religion (City of Boerne v. Flores 1997 limited RFRA to federal action). Fulton v. Philadelphia (2021) signaled an appetite to reconsider Smith; the Court instead held that the Philadelphia foster-care system was not generally applicable. Tandon v. Newsom (2021) sharpened the comparator analysis: a law is not generally applicable if it treats any comparable secular activity more favorably than religious exercise.

Originalism interprets constitutional text by its 'original public meaning' at the time of ratification. Textualism, its statutory cousin, focuses on the meaning of statutory words rather than legislative intent or purpose. Both methodologies are now dominant on the Roberts Court. Justice Scalia popularized them; Justices Thomas, Alito, Gorsuch, Kavanaugh, and Barrett apply them with varying intensity. Bruen (2022) explicitly demands a 'text, history, and tradition' analysis for Second Amendment challenges.

When an agency claims authority to decide an issue of vast 'economic and political significance,' it must point to clear congressional authorization. West Virginia v. EPA (2022) formally named the doctrine and used it to invalidate the Obama-era Clean Power Plan; Biden v. Nebraska (2023) used it to strike the student-loan forgiveness program. The doctrine is doing much of the work that a revived non-delegation doctrine might otherwise do — without the constitutional difficulty of telling Congress what it cannot delegate.

Chevron v. NRDC (1984) instructed courts to defer to a federal agency's reasonable interpretation of an ambiguous statute it administers. For forty years Chevron structured the administrative state. In Loper Bright Enterprises v. Raimondo (2024) the Court overruled Chevron, holding that courts must exercise independent judgment in interpreting statutes — agencies receive at most Skidmore-style respect proportionate to the persuasiveness of their reasoning. Loper Bright is the most consequential administrative-law decision in a generation; combined with the major questions doctrine and a revived non-delegation impulse, it shifts interpretive authority decisively from agencies to courts.

The Roberts Court has imported a 'history and tradition' methodology across multiple constitutional clauses: Bruen (2022) for the Second Amendment, Kennedy v. Bremerton (2022) for the Establishment Clause, Dobbs (2022) for substantive due process. The unifying move is to replace balancing tests and tiered scrutiny with analogical reasoning to founding-era practice. Critics argue this freezes constitutional meaning to a moment when most Americans were excluded; defenders argue it disciplines judicial discretion.