Connecticut’s two largest tribal casinos, Foxwoods & Mohegan Sun, are threatening to cut off slot machine revenue from their casino resorts if sports betting is authorized statewide. In a letter to House Speaker Joe Aresimowicz, D-Berlin, and other legislative leaders, the Mohegan and Mashantucket Pequot tribes said a bill before the General Assembly to legalize sports betting would violate the compact between the tribes and the state. That means the state’s 25 percent take from slot revenue at the Foxwoods and Mohegan Sun casinos — some $250 million a year — could be cut off unless a deal is struck…