Maryland legislators will be cutting their summer vacations short after Gov. Martin O'Malley announced a special session for Aug. 9 to address gambling questions left unanswered in the spring. But after Mr. O'Malley repeatedly urged state leaders to “put the issues behind us so we can move forward,” some people are wondering whether the decision was a risky bluff. It’s the second special session this summer — Mr. O'Malley called the first one in mid-May to wrap up the budget — and the issues of table game expansion at Maryland’s existing casinos and adding a sixth casino in Prince George’s...