In Murphy v. NCAA, the Supreme Court’s 2018 sports betting ruling struck down the Professional and Amateur Sports Protection Act (PASPA), the 1992 federal law that had blocked nearly every state from legalizing wagering on sporting events. Writing for a seven-justice majority on the core constitutional question, Justice Samuel Alito held that PASPA violated the anti-commandeering doctrine because it ordered state legislatures to keep their own gambling prohibitions in place.1Supreme Court of the United States. Murphy v. National Collegiate Athletic Assn. The decision did not legalize sports betting nationwide. It simply removed the federal barrier and handed the question back to each state.
The Federal Law the Court Struck Down
Congress passed PASPA in 1992. The statute made it unlawful for any state or local government to sponsor, operate, or authorize betting on competitive sporting events, and it barred private parties from running sports wagering under state authority.2Office of the Law Revision Counsel. 28 USC Ch. 178: Professional and Amateur Sports Protection PASPA never made it a crime for an individual to place a sports bet. The target was state governments and operators.
The law included grandfather provisions for states that already permitted some form of sports wagering. Nevada, Delaware, Oregon, and Montana qualified, but only Nevada could offer full single-game sports betting through its casinos. The other three states were limited to narrower products like sports lotteries and parlay cards. Every other state was locked out. Parimutuel wagering on horse racing and jai alai had its own carve-out and continued under the Interstate Horseracing Act.
How the Case Reached the Supreme Court
New Jersey drove the challenge. In 2011, sixty-four percent of the state’s voters approved a referendum allowing sports gambling at casinos and racetracks, and the legislature passed the Sports Wagering Act in January 2012.1Supreme Court of the United States. Murphy v. National Collegiate Athletic Assn. The NCAA, NFL, NBA, NHL, and MLB sued under PASPA. A federal district court struck the law down, and the Third Circuit affirmed.
New Jersey tried a second approach in 2014. Rather than affirmatively authorizing sports betting, the new law repealed the state’s own prohibitions on wagering at casinos and racetracks. The theory: if PASPA barred states from “authorizing” sports betting, a state might comply by simply stepping out of the way. The Third Circuit rejected that argument too, holding that a partial repeal amounted to authorization. But the litigation had crystallized the question that reached the Supreme Court: can Congress force a state to keep a law on its books?
The Anti-Commandeering Holding
The Tenth Amendment reserves to the states all legislative powers the Constitution does not grant to Congress.3Justia. Murphy v. National Collegiate Athletic Association, 584 U.S. (2018) Building on that foundation, the anti-commandeering doctrine holds that Congress can regulate private conduct through federal law but cannot order state legislatures to enact, enforce, or maintain a particular regulatory program.
The Court had applied the principle before. New York v. United States (1992) struck down a federal provision forcing states either to regulate radioactive waste according to Congress’s instructions or to take ownership of the waste. Printz v. United States (1997) invalidated a Brady Act provision that conscripted local sheriffs to run federal firearm background checks. Both cases stood for the same rule: the federal government cannot dragoon state officials into administering federal policy.
Justice Alito’s majority opinion, decided May 14, 2018, applied that rule to PASPA. Congress had the power to regulate sports gambling directly through federal law, the Court explained, but it could not regulate how a state regulates its own citizens. PASPA did not create a federal prohibition on sports betting. It issued a command to state legislatures telling them they could not pass new laws authorizing it, and that command crossed the constitutional line.3Justia. Murphy v. National Collegiate Athletic Association, 584 U.S. (2018)
Seven justices joined the core anti-commandeering holding. Justices Ginsburg and Sotomayor dissented. The Court then asked whether the unconstitutional provisions could be severed from the rest of PASPA, leaving other parts of the statute intact. Six justices said no. Justice Breyer agreed with the anti-commandeering ruling but believed the remaining provisions were severable. The majority concluded the statute could not be surgically preserved, and PASPA fell in full.1Supreme Court of the United States. Murphy v. National Collegiate Athletic Assn.
What Changed for Sports Betting After the Ruling
States moved fast. New Jersey launched legal sports betting within weeks. Delaware, Mississippi, and West Virginia followed before the end of 2018. By 2026, more than 40 states and the District of Columbia had legalized some form of sports wagering, and legal U.S. sportsbooks generated roughly $17 billion in gross revenue during 2025 on a total handle of nearly $167 billion.
Regulation and taxation vary widely by state. Tax rates on gross sports betting revenue run from 6.75 percent in Nevada and Iowa to 51 percent in New York, New Hampshire, Oregon, and Rhode Island. Several states have raised rates recently. Illinois moved its online sports betting tax from 15 percent to 40 percent and added a per-wager surcharge. New Jersey, the state that brought the case, raised its online rate from 14.25 to 21 percent.
Most states set the minimum age for sports betting at 21. A handful set it at 18, including Montana, New Hampshire, Ohio, Rhode Island, and Wyoming. States that allow online wagering typically require operators to use geolocation technology to confirm the bettor is within state lines at the moment of each bet, along with identity verification, self-exclusion options for problem gamblers, and responsible gaming disclosures.
Federal Laws That Still Apply
Murphy eliminated PASPA. It did not clear the entire federal field. Two statutes still shape what states and operators can do.
The Wire Act
The Wire Act of 1961 makes it a federal crime for anyone in the betting business to use a wire communication facility to transmit bets, wagers, or information assisting in placing bets on sporting events across state lines, with penalties of up to two years in prison.4Office of the Law Revision Counsel. 18 U.S. Code 1084 – Transmission of Wagering Information; Penalties The statute has a safe harbor for transmissions between two jurisdictions where the betting is legal in both.
The Wire Act’s reach has been contested at the Department of Justice. A 2011 DOJ opinion concluded the law applied only to sports betting. In 2018, DOJ reversed and read the Wire Act to cover all forms of online gambling.5U.S. Department of Justice. Reconsidering Whether the Wire Act Applies to Non-Sports Gambling The First Circuit rejected the broader reading and held that the Wire Act applies only to sports wagering. DOJ chose not to appeal. In practice, the Wire Act is the main reason legal sports betting operates state by state rather than across state lines; each state’s licensed market is largely a walled garden.
The Unlawful Internet Gambling Enforcement Act
The Unlawful Internet Gambling Enforcement Act of 2006 (UIGEA) does not ban online gambling directly. It targets the money. Financial institutions and payment processors must maintain policies designed to identify and block transactions connected to unlawful internet gambling.6eCFR. Part 233 – Prohibition on Funding of Unlawful Internet Gambling (Regulation GG) The critical word is “unlawful.” Transactions through operators licensed under a state’s legal sports betting regime are lawful, and UIGEA does not block them. For unlicensed offshore books, UIGEA gives banks and payment networks both the authority and the obligation to shut off the money flow.
Tribal Gaming After Murphy
Murphy created a distinct set of questions for tribal gaming. Under the Indian Gaming Regulatory Act, tribes can offer Class III gaming (the category that includes sports betting) only if the activity is authorized by tribal ordinance, located in a state that permits such gaming, and conducted under a tribal-state compact negotiated in good faith with the state.7National Indian Gaming Commission. Indian Gaming Regulatory Act
Before Murphy, this was mostly academic for sports betting because PASPA blocked it outside Nevada. Afterward, tribes in newly legalizing states needed either amended compacts or new ones covering sports wagering. Some states moved quickly, and tribes launched books soon after. In others, disputes over whether tribes can offer mobile wagering statewide or only on tribal land have produced extended legal fights. The friction between state-licensed commercial operators and tribal gaming rights is one of the more complicated ongoing consequences of the ruling.
Why the Ruling Matters Beyond Sports Betting
Murphy was decided as a sports betting case, but its most durable influence is likely in constitutional law. Before Murphy, the anti-commandeering doctrine had been applied in relatively narrow settings: radioactive waste disposal and firearm background checks. Murphy extended the principle to a broader context by holding that Congress cannot prevent a state from repealing its own laws, even when the repeal effectively allows conduct Congress disfavors.
That reasoning reaches well past gambling. Any federal statute that depends on states maintaining their own prohibitions, rather than establishing a direct federal ban enforced by federal officers, is vulnerable to the same challenge. Murphy reinforced a structural feature of American government that is easy to overlook: the federal government and state governments are separate sovereigns, and neither can conscript the other into its regulatory agenda.1Supreme Court of the United States. Murphy v. National Collegiate Athletic Assn.