Gov. Martin O’Malley has called for a special legislative session on gambling next month in what the Baltimore Sun has dubbed “a high-stakes political bet that he can prevail in a struggle over one of the most contentious issues facing Maryland.” O’Malley would like to expand gambling in Maryland through a proposal that he says would add $100 million in revenue to next year’s state budget. A win could bolster his image as an effective leader both within the state and nationally. But what are his chances? Donald F. Norris, professor and chairman of UMBC’s Department of Public Policy, told …