The NFL’s Miami Dolphins waded into the midterm elections this week, urging Florida voters to reject a ballot measure on Tuesday that would make it more difficult for the state to legalize sports betting.

If approved, Amendment 3 would require that any attempt to expand casino gambling be subject to a voter referendum rather than through a bill from the state legislature. In a message to fans on Monday, the Dolphins argued that the amendment, if passed, would “effectively block any chance for legal sports betting in Florida.”

Several major companies took stances on the amendment ahead of voting Tuesday. The Walt Disney Company and Hard Rock International, the latter of which controls naming rights for the Dolphins’ home stadium, are in favor of the amendment. The Dolphins, as well as sportsbook operators FanDuel and DraftKings, have actively lobbied against the amendment.

Several states, including New Jersey and Delaware, have already entered the sports betting market since the U.S. Supreme Court struck down a federal ban on the controversial pastime last May. The court’s ruling allows states to determine whether to legalize sports betting on an individual basis.

rominent U.S. sports leagues opposed legalized sports betting for decades, but most, including the NBA, NHL and individual NFL teams, have begun to integrate gambling into their events. The NFL has called on Congress to regulate sports betting at the federal level.

A fully legalized, regulated sports betting industry could be worth up to $2.3 billion to the NFL annually, according to a study last September by Nielsen Sports commissioned by the American Gaming Association.