A federal judge has issued an emergency order blocking Arizona from proceeding with the first criminal arraignment of a prediction market operator in U.S. history. The ruling, favoring the Commodity Futures Trading Commission (CFTC), underscores the federal agency's authority over event contracts, which Arizona sought to regulate as gambling. U.S. District Judge Michael Liburdi granted the temporary restraining order, citing the likelihood of the CFTC's success in arguing that Arizona's gambling laws are preempted by the Commodity Exchange Act. Arizona Attorney General Kris Mayes had filed 20 criminal charges against KalshiEx LLC and Kalshi Trading LLC, alleging illegal wagers on sports and political outcomes. The CFTC, supported by the Department of Justice, contended that Arizona's actions interfered with its exclusive federal jurisdiction over swaps traded on designated contract markets. The temporary restraining order remains in effect until April 24, with a hearing scheduled to consider extending the block on state prosecution.