The Tenth and Fourteenth Amendments together set the ground rules for American federalism. The Tenth Amendment reserves to the states any power the Constitution doesn’t hand to the federal government, giving states broad authority over daily life. The Fourteenth Amendment then draws a line around that authority: no state may deny citizenship, due process, or equal protection to any person within its borders. One grants the power; the other limits how it can be used.
What the Tenth Amendment Reserves to the States
The Tenth Amendment says that powers not given to the federal government and not denied to the states belong to the states or to the people.1Congress.gov. Tenth Amendment That creates a default: the federal government can act only where the Constitution grants specific permission — regulating interstate commerce, declaring war, collecting taxes. Everything else falls to the states.
What states retain is called the police power, and it is remarkably broad. States can pass laws promoting public health, safety, and general welfare within their borders. Your state, not the federal government, sets speed limits on local roads, defines most criminal offenses, runs the public school system, issues professional licenses, and regulates landlord-tenant relationships. States also handle family law, property rights, and management of local natural resources.
The Supreme Court recognized early on that states control purely internal affairs. In Gibbons v. Ogden (1824), the Court confirmed that health laws, inspection requirements, and regulation of commerce within a single state fall outside federal power.2Justia U.S. Supreme Court Center. Gibbons v. Ogden The police power also reaches public health emergencies. In Jacobson v. Massachusetts (1905), the Court upheld a city’s mandatory smallpox vaccination requirement, ruling that states can impose reasonable health regulations to protect the population.3Justia U.S. Supreme Court Center. Jacobson v. Massachusetts, 197 U.S. 11 (1905) Most laws you encounter day to day come from state or local authority rooted in the Tenth Amendment.
What the Fourteenth Amendment Guarantees Against the States
Ratified in 1868 after the Civil War, the Fourteenth Amendment fundamentally changed the relationship between states and the people who live in them. It was part of the Reconstruction-era effort to guarantee equal civil and legal rights to formerly enslaved people, and its first section contains four distinct protections that now apply far more broadly.4National Archives. 14th Amendment to the U.S. Constitution – Civil Rights (1868)
The Citizenship Clause makes anyone born or naturalized in the United States a citizen of both the nation and the state where they live, blocking states from creating second-class citizenship or stripping residents of their status. The Privileges or Immunities Clause bars states from undercutting the basic rights of national citizenship, though the Supreme Court read it narrowly early on and it has played a limited role since.5Congress.gov. Modern Doctrine on Privileges or Immunities Clause The Due Process Clause forbids any state from depriving a person of life, liberty, or property without fair legal procedures. The Equal Protection Clause requires states to treat people in similar circumstances consistently and forbids arbitrary or discriminatory treatment of groups.6Congress.gov. Fourteenth Amendment
One boundary matters at the outset. These protections reach only government action. The Fourteenth Amendment restricts state legislators, police officers, judges, and government agencies; it does not, by itself, reach purely private conduct. As the Court has put it, the amendment “erects no shield against merely private conduct, however discriminatory or wrongful.”7Legal Information Institute. State Action Doctrine A private employer who discriminates may violate civil rights statutes, but a Fourteenth Amendment claim needs some connection to government authority.
How the Bill of Rights Reaches States Through the Fourteenth Amendment
When the Bill of Rights was ratified in 1791, it only restricted the federal government. The Supreme Court made that explicit in Barron v. Baltimore (1833), holding that the Fifth Amendment’s takings protection did not apply to city or state governments.8Justia U.S. Supreme Court Center. Barron v. Mayor and City Council of Baltimore For decades, states could restrict speech, conduct unreasonable searches, or deny counsel to criminal defendants without violating the federal Constitution.
The Fourteenth Amendment changed that. Using its Due Process Clause, the Supreme Court began ruling that specific protections in the Bill of Rights are so fundamental to liberty that states must honor them too. The process, called incorporation, has played out one right at a time over more than a century.9Congress.gov. Overview of Incorporation of the Bill of Rights The Court rejected the idea of applying the entire Bill of Rights to states at once, instead evaluating each right individually.
Two landmark cases show what incorporation did to state criminal law. In Gideon v. Wainwright (1963), the Court held that the Sixth Amendment right to counsel is so fundamental that states must provide attorneys for defendants who cannot afford one. A conviction obtained without offering counsel to an indigent defendant gets thrown out on appeal.10Justia U.S. Supreme Court Center. Gideon v. Wainwright Later cases refined the rule: you cannot be sentenced to any term of imprisonment unless you had a lawyer or knowingly waived that right, regardless of whether the charge was a felony or misdemeanor.11Legal Information Institute. Modern Doctrine on Right to Have Counsel Appointed
In Mapp v. Ohio (1961), the Court applied the exclusionary rule to state courts, meaning evidence police obtain through an unconstitutional search must be thrown out of the criminal case, even if it clearly proves guilt.12Justia U.S. Supreme Court Center. Mapp v. Ohio, 367 U.S. 643 (1961) Before Mapp, many state courts freely admitted illegally obtained evidence. After it, the floor for police conduct became uniform nationwide.
Most of the Bill of Rights now applies to the states, but a few provisions remain unincorporated. The Third Amendment’s ban on quartering soldiers has never been tested at the state level. The Seventh Amendment right to a civil jury trial does not bind state courts. And the Fifth Amendment’s grand jury indictment requirement has not been extended to state prosecutions, so many states use a prosecutor’s filing to bring felony charges.
Substantive Due Process and Unenumerated Rights
The Due Process Clause protects more than fair procedures. The Supreme Court has interpreted it to shield certain fundamental rights that appear nowhere in the Constitution’s text. This doctrine, called substantive due process, recognizes that some personal liberties are so deeply embedded in American life that the government cannot override them regardless of how fair the procedure.
Rights the Court has recognized under this doctrine include the right to marry, the right of parents to direct the upbringing of their children, the right to privacy, the right to use contraception, and the right to refuse unwanted medical treatment. In an earlier era, the Court also protected economic rights like “freedom of contract” this way, but it abandoned that approach in 1937 and now focuses on personal and relational rights rather than business regulations.
For a claimed right to qualify as fundamental, the test the Court set out in Washington v. Glucksberg (1997) requires it to be deeply rooted in American history and tradition. The Court’s 2022 decision in Dobbs v. Jackson Women’s Health Organization reinforced and tightened that framework when it overturned the constitutional right to abortion, emphasizing that unenumerated rights must be grounded in historical practice rather than evolving social views. The majority said the ruling applied only to abortion and did not disturb other substantive due process precedents, but the decision signaled a more skeptical posture toward claims of new unenumerated rights.
Limits That Run Both Ways
The Tenth Amendment reserves power to the states, but it does not make that power absolute. Several doctrines constrain what states can do, and one important doctrine constrains what the federal government can demand of states.
Federal Preemption
The Supremacy Clause in Article VI makes federal law the “supreme law of the land,” so valid federal legislation overrides conflicting state laws. Congress can expressly state that federal law overrides state regulation in a particular area. Even without explicit language, federal law can impliedly preempt state rules when a federal regulatory scheme is so comprehensive it leaves no room for state involvement, or when complying with both requirements at once is impossible.13Congress.gov. Federal Preemption – A Legal Primer Immigration enforcement, nuclear energy regulation, and parts of financial regulation are common examples.
The Dormant Commerce Clause
Even where Congress has not legislated, states cannot pass laws that discriminate against or place excessive burdens on interstate commerce. The Supreme Court struck down a Massachusetts tax on milk products in West Lynn Creamery v. Healy (1994) because it discriminated against out-of-state dairy producers. States retain significant room to regulate matters within their borders even when those regulations have some effect on commerce across state lines, so long as the regulation does not discriminate or create an undue burden.
The Anti-Commandeering Doctrine
The Tenth Amendment cuts in the other direction too. Under the anti-commandeering doctrine, Congress cannot order state legislatures to pass specific laws or draft state officials into administering federal programs. The Court established this principle in New York v. United States (1992), holding that Congress cannot “commandeer the legislative processes of the States by directly compelling them to enact and enforce a federal regulatory program.”14Justia U.S. Supreme Court Center. New York v. United States, 505 U.S. 144 (1992)
Five years later, Printz v. United States (1997) extended the rule to state executive officials. The Court struck down a provision of the Brady Act that required local sheriffs to conduct background checks on handgun purchasers, ruling that the federal government “may neither issue directives requiring the States to address particular problems, nor command the States’ officers … to administer or enforce a federal regulatory program.”15Legal Information Institute. Printz v. United States, 521 U.S. 898 (1997)
The Court broadened the doctrine in Murphy v. NCAA (2018), striking down a federal law that prohibited states from authorizing sports gambling. The anti-commandeering rule applies equally to laws that tell states what they must do and laws that tell states what they may not legislate. Congress cannot dictate the content of state law in either direction.16Supreme Court of the United States. Murphy v. National Collegiate Athletic Association (2018) Congress can regulate individuals directly through federal law, offer funding incentives, or use other tools, but it cannot treat state governments as administrative arms of the federal bureaucracy.
How Courts Evaluate State Laws That Affect Constitutional Rights
When someone challenges a state law under the Fourteenth Amendment, courts do not use one universal test. The level of skepticism depends on what kind of right or classification the law affects, and the framework has three tiers.
Under rational basis review, the government only needs to show that the law is reasonably related to a legitimate purpose. Courts do not second-guess whether the law is wise policy. Economic regulations, licensing requirements, and general welfare legislation almost always survive. In rare cases, courts have applied a more demanding version when a law appears motivated by hostility toward a particular group rather than any legitimate policy goal.
Intermediate scrutiny applies to laws that classify people by gender or similar characteristics. The government must show the law furthers an important objective and that the classification is substantially related to achieving it. That standard prevents states from relying on broad stereotypes about men and women to justify different treatment.
Strict scrutiny is the most demanding standard, and it applies when a law infringes a fundamental right or classifies people by race, national origin, religion, or alienage. The government must prove the law serves a compelling interest and is narrowly tailored to achieve that interest through the least restrictive means available. Most laws subjected to strict scrutiny fail.
How People Enforce Their Fourteenth Amendment Rights
Knowing rights exist and actually enforcing them are different problems. The main tool for holding state officials accountable is 42 U.S.C. § 1983, a federal statute that lets individuals sue anyone who, acting under government authority, deprives them of rights secured by the Constitution.17Office of the Law Revision Counsel. 42 U.S. Code 1983 – Civil Action for Deprivation of Rights This is the statute behind most civil rights lawsuits against police officers, prison officials, public school administrators, and other government actors.
To win a Section 1983 claim, you must prove two things: the defendant was acting “under color of” state law, meaning they were using government authority rather than acting as a private citizen, and their conduct violated a specific constitutional right. Successful plaintiffs can recover compensatory damages for financial losses, emotional harm, and reputational injury. Courts can also award punitive damages when an official acted with reckless disregard for constitutional rights, and the prevailing party may recover attorney’s fees.18Office of the Law Revision Counsel. 42 USC 1988
Qualified Immunity
The biggest practical hurdle in Section 1983 cases is qualified immunity. This court-created doctrine shields government officials from personal liability unless they violated a “clearly established” constitutional right, meaning a prior court decision must have already held that substantially similar conduct was unconstitutional. An officer who violates your rights in a novel way that no court has previously addressed can escape liability even if the conduct was objectively unreasonable. Qualified immunity is decided early in the lawsuit, often before any evidence gathering takes place, and it knocks out a significant share of civil rights cases.
Suing a City or County
You can sue a local government under Section 1983, but not simply because one of its employees violated your rights. The Supreme Court held in Monell v. Department of Social Services (1978) that a local government is liable only when the constitutional violation resulted from an official policy, a widespread custom, or a decision by someone with policymaking authority.19Justia U.S. Supreme Court Center. Monell v. Department of Social Services A city is not responsible just because it employs the person who harmed you. You have to connect the violation to something systemic — a training failure, a pattern of misconduct the city tolerated, or an explicit policy that caused the harm.
Congress’s Enforcement Power
The Fourteenth Amendment does not only empower courts. Section 5 gives Congress the authority to enforce the amendment’s protections “by appropriate legislation.” That is the constitutional foundation for major civil rights statutes, including laws prohibiting employment discrimination and protecting voting rights. Congress’s power is not unlimited. The Supreme Court held in City of Boerne v. Flores (1997) that enforcement legislation must be proportionate and congruent to the constitutional violations Congress is trying to remedy or prevent.20Congress.gov. Modern Doctrine on Enforcement Clause Congress must show a pattern of the specific constitutional violation it seeks to address, and its legislative response cannot be wildly out of proportion to the documented problem.