145 tribal amici urge Supreme Court to reject Kalshi’s sports contracts

A coalition of 145 Indian Tribes and tribal organizations has urged the Supreme Court to back challengers to Kalshi’s sports event contracts, arguing that the prediction-market company is encroaching on tribal authority over gaming and threatening a crucial source of government revenue.

The filing in Supreme Court case No. 26-299 supports petitioners Mary Jo Flaherty and Jennifer Davenport in their dispute with KalshiEX, LLC. Its signatories comprise 130 federally recognized Tribes and 15 tribal organizations, making it a broad intervention in litigation over whether sports-focused event contracts should be treated as federally regulated financial products or gambling.

The Muscogee (Creek) Nation is among the opponents, according to Mvskoke Media. Jonodev Chaudhuri, the Nation’s ambassador, said such markets could introduce unregulated gaming into the Nation’s territory and divert money that should be governed under Indian gaming law and used for services to tribal citizens.

The tribal brief contends that Kalshi’s sports contracts are Class III gaming under the Indian Gaming Regulatory Act. It says IGRA, enacted in 1988, protects tribal authority to regulate gaming on Indian lands where it is otherwise allowed, and requires Class III gaming to have tribal authorization, tribal ordinances and, where applicable, a tribal-state compact or federally prescribed procedures.

The filing frames the issue as one of self-government as well as commercial competition. It argues that Kalshi and similar platforms offer sports betting on Indian lands without tribal consent, directly competing with tribal sports betting and undermining tribal sovereignty. Gaming revenue, the brief says, supports health care, housing, education, law enforcement and other government services in tribal communities.

Tribal governments spend more than $450 million a year on gaming regulation and employ more than 6,000 gaming regulators, the brief says. It adds that gaming has become a critical source of revenue and a means of reinforcing tribal self-governance, particularly given what it describes as the federal government’s unmet trust and treaty obligations.

Kalshi’s legal position has found support at the Third Circuit. In April, the court held that the company had a reasonable chance of showing that the Commodity Exchange Act pre-empted applicable New Jersey law. The court characterized Kalshi’s contracts as swaps traded on a Commodity Futures Trading Commission-licensed designated contract market, and said state laws that directly interfere with such swaps are pre-empted.

That differs sharply from the tribes’ position that the substance of a sports event contract, rather than its label, makes it gaming when it is accessed on Indian lands. Prediction-market proponents have similarly argued that the instruments are financial contracts whose value depends on an event outcome, rather than gambling products.

The brief also arrives amid differing tribal approaches to Kalshi’s platform. Kalshi announced this month that four tribal entities would launch independently branded applications using its exchange infrastructure, presenting the ventures as potential economic-development tools. But the Alabama-Quassarte Tribal Town later denied that it had signed an agreement with Kalshi, as our earlier report covered.

The Indian Gaming Association has urged Tribes to coordinate amicus briefs in disputes over prediction markets, arguing that calling a wager an event contract does not remove the authority of tribal and state governments to regulate gambling.