Boston - The contentious issue of whether to expand gambling in Massachusetts could be back on the Statehouse's agenda this summer, driven by the Mashpee Wampanoag's effort to build an American Indian casino in Middleboro. The House seemingly dealt casinos a fatal blow in March, defeating Gov. Deval Patrick's plan for three commercial casinos by a lopsided vote of 108-46. But Statehouse insiders are now looking at three new fronts in the battle, which will unfold over the coming months: