The need to generate additional state revenue is creating new support for expanding gambling in Massachusetts, observers say. Lawmakers said they will hold hearings on the issue in the fall. Proposals to expand gambling have faced stiff opposition in previous years, but lawmakers from both parties expect some form of gambling legislation to pass this year. "I think we'll see a real nasty debate," said Clyde W. Barrow, head of UMass-Dartmouth's Center for Policy Analysis. But, he added, "it's pretty clear something is going to pass."