37 states back Massachusetts saying CFTC can't override gambling laws without Congress

The fight over prediction markets just turned into a states vs federal power battle. A 37-state coalition plus D.C. is backing Massachusetts, arguing gambling regulation has always sat with states, not automatically with the CFTC.

What changed is how explicitly they’re drawing the line: if the federal government wants to override state gambling laws, Congress has to say so directly. The brief leans on the “major questions” doctrine, basically saying the CFTC can’t claim sweeping authority over these markets without clear authorization.

This widens the case from one lawsuit filed in September into a national stance. Ohio and Nevada co-led the filing, framing Kalshi’s event contracts as something states should control, not just another federally regulated derivatives product.