Federal Preemption: The Legal Fight That Decides Prediction Markets' Future

The most important legal question in prediction markets is not whether betting on elections is wise. It is whether a federal agency can override a state's gambling law. If the answer is yes, platforms like Polymarket and Kalshi can operate nationwide under CFTC rules. If the answer is no, they face a state-by-state patchwork of licences, bans and lawsuits.

The legal doctrine is called preemption. It comes from the Supremacy Clause of the US Constitution: federal law prevails over conflicting state law. The Commodity Exchange Act gives the CFTC exclusive jurisdiction over designated contract markets. The question is whether that exclusivity covers event contracts that look like sports bets.

The case for preemption

The companies and the CFTC argue that event contracts are derivatives, not gambling. They are listed on a federally regulated exchange, cleared through a regulated clearinghouse and traded by market participants who may be hedging risk. The CFTC approves the contracts and supervises the exchange.

If a state can ban a federally approved contract, the argument goes, the national market cannot function. A single state attorney general could shut down a product that the federal regulator has authorised. That would undermine the purpose of federal derivatives regulation.

In 2024, a federal district court in Washington, DC ruled that the CFTC had exceeded its authority when it tried to block Kalshi's congressional control contracts. The court found that the agency's reasoning was flawed. The decision allowed Kalshi to relaunch election markets and became a foundation for later preemption arguments.

In 2026, federal judges in Arizona and Minnesota accepted the preemption argument. The Arizona criminal case against Kalshi was dismissed. The Minnesota ban was blocked.

The case against preemption

States argue that gambling is a traditional police power, not a federal financial market. They say event contracts on sports, elections and entertainment are functionally bets, and that the CFTC does not have the resources or the mandate to police them as gambling.

Massachusetts obtained a preliminary injunction against Kalshi's sports contracts in January 2026. Nevada, Ohio and Washington issued similar rulings. The Massachusetts attorney general's office argued that the state's gambling laws apply regardless of how the product is labelled.

States also raise consumer protection concerns. Gambling regulators require age limits, self-exclusion tools, advertising rules and dispute procedures. Prediction markets, they argue, offer a lighter-touch federal regime that is not equivalent.

The CFTC's counter-offensive

In 2026 the CFTC, under chairman Michael Selig, sued several states that had moved against prediction markets. The agency argued that states cannot interfere with federally regulated markets. It filed actions against New York, Wisconsin, Arizona, Connecticut, Illinois, Massachusetts and Minnesota.

President Trump publicly supported the CFTC's position, saying it was "critically important" that the federal government retain exclusive authority over prediction markets. That political support strengthens the agency's hand but also makes the issue partisan.

The state regulators article covers the individual cases.

Why the courts are split

Preemption cases turn on specific facts: what the contract says, how it settles, whether it is marketed as a bet, and whether the state law conflicts directly with federal regulation. A contract that references a sports score may look different from a contract on an economic indicator, even if both are traded on the same exchange.

The procedural posture also matters. A state court may be more receptive to a state gambling argument than a federal court. A federal judge may be more receptive to a federal agency's view. The result is a patchwork of rulings that depends on where the case is filed.

The major questions problem

Even if the Commodity Exchange Act gives the CFTC broad authority, courts may ask whether the agency has clearly been authorised to regulate sports betting under the guise of event contracts. The "major questions" doctrine, used by the Supreme Court in several recent cases, requires Congress to speak clearly on issues of major economic and political significance.

Prediction markets could qualify. They involve billions of dollars, touch gambling law and raise questions about election integrity. A court could conclude that the CFTC's authority is not clear enough.

The companies argue that event contracts are a longstanding category of derivatives and that the CFTC has regulated them for years. The states argue that sports betting is a new use that Congress did not authorise.

What happens next

Three paths are plausible.

First, the Supreme Court takes a case and settles the question. That would be the cleanest outcome, but it could take years.

Second, Congress passes a law clarifying the CFTC's authority. That is unlikely in the current political environment, where prediction-market legislation is divided and the Trump family has financial interests in the industry.

Third, the patchwork persists. Platforms geoblock some states, fight others and adapt their product lists. Traders face uneven access and uncertainty.

The 2027 regulation outlook considers each scenario.

What it means for traders

Preemption is not an abstract legal debate. It determines whether you can open a position, whether you can close it and whether the platform will still be available in your state next month.

The practical advice is to assume access can change. Do not keep more funds on a platform than you need. Keep records. Read the terms. And avoid markets whose legality depends on a court ruling that could be reversed.

The Polymarket vs Kalshi comparison shows how the two companies are exposed to the same legal question in different ways. Kalshi's entire US business depends on preemption. Polymarket's global business depends on not being treated as a US gambling operator. Both are bets on the same legal theory.