LYNN – At least one of Lynn’s legislators supports State Treasurer Timothy Cahill’s proposal Thursday to beat the Mashpee Wampanoag Indians into the casino business by partnering with private developers to build one or more resort casinos in a bid to generate up to $1 billion in annual revenue.Cahill, a close ally of Gov. Deval Patrick, said the state’s lottery revenue is stagnant and Massachusetts residents are spending significant dollars at the two casinos in Connecticut and slot parlors in Rhode Island.His proposal came on the same day that the Mashpee Wampanoags’ federal recognition as a tribe takes effect.”The Wam-panoag issue has changed the dynamic,” Cahill said after his speech before the Greater Boston Chamber of Commerce. “They’re going to be allowed to do this somewhere, somehow, someday, so I think we need to get out in front of it.”The Cape Cod-based Mashpee Wampanoags have already purchased options on land in Middleborough to possibly open a casino by 2010. The tribe is also considering New Bedford as a site for a casino.State Rep. Robert Fennell, a Lynn Democrat, said any decision by the state to own and operate casinos should be preceded by plenty of research.”I have always felt the state should control it, because if you control the amount of money taken in, you control the profit you make,” he said. “The slot machines and everything else could be run from a central office.”Fennell noted that Indian tribes in Connecticut give the state a portion of the proceeds, but keep the larger share.”The treasurer is saying he would have a casino company come in and build it and the state would give a percentage to the operator. But at least the state would own it,” he said.The scenario differs from that geared toward slot machines at racetracks, he said, explaining that state-owned, state-run slot machines give a small portion of the proceeds to the track for permission to keep the machines on the premises.Fennell said the Legislature should move cautiously because opening the door to casino ownership statewide could set off a land grab and unhealthy competition. “Everyone is going to want one in their own back yard,” he said. “Casinos are destination places. If you build one in Boston, why would somebody who lives around here travel to Worcester?”State Sen. Thomas McGee, also a Lynn Democrat, said as of the last session of the Legislature, two-thirds of the Senate, himself included, voted in support of slot machines at racetracks.”It was a well thought out plan,” he said. “I think it’s too early to talk about what a casino plan would look like. The governor has people looking into what proposals are out there.”Any full-scale casino needs legislative approval. Patrick has appointed a task force to examine whether to support an expansion of legal gambling beyond the state lottery and the state’s horse and dog tracks. He expects the report by the end of the summer.Senate President Therese Murray, D-Plymouth, has been supportive of expanded gambling, but House Speaker Salvatore DiMasi, D-Boston, has opposed it in the past. Cahill said DiMasi would be the hardest sell, but Patrick would be receptive because “the governor is looking for more revenue.”Doug Rubin, Patrick’s chief of staff and former top lieutenant in Cahill’s office, attended the speech but declined immediate comment.Tribe spokesman Scott Ferson, who also attended, predicted a “photo finish” on who would be first to build a casino should the Legislature approve expanded gambling.”To have a constitutional officer endorse the concept that we’ve been putting forth is encouraging,” he said.Casino gambling opponent Rep. Dan Bosley said Cahill’s proposal was an “ill-conceived” overreaction to flat lottery revenues. The Wampanoags would soon build a competing casino, he said, and the state’s revenues could be eroded further by future projects by other tribes.It’s a myth that states can “recapture” gambling revenue residents spend elsewhere, said Bosley, citing the co