The resignation of House Speaker Salvatore DiMasi, an avowed opponent of casino gambling, was barely official last week before eyes on Beacon Hill turned to the renewed potential of bringing three casinos to the Bay State.

DiMasi's successor, Rep. Robert DeLeo, is a supporter of slots at the state's racetracks and is open to discussing casinos. Last year, under DiMasi's watch and direction, House lawmakers overwhelmingly defeated Gov. Deval Patrick's proposal to expand gambling.

Dorchester lawmakers are likely to play key roles in the debate, as they did in the last round of casino talks. At last year's St. Patrick's Day breakfast, state Sen. Jack Hart and Reps. Marty Walsh and Brian Wallace - all casino supporters - joined Patrick in jokingly serenading DiMasi to convince him of all the good casinos can do.

Indeed, Walsh and Wallace, both known as pro-union lawmakers, wasted no time after DiMasi's resignation. They jointly filed a bill last week similar to Patrick's legislation from last year. They say the casinos will introduce "thousands" of new jobs and "hundreds of millions of dollars in new revenue" for the state, which is badly reeling from a shaky economy. The casinos would be located in western and southeastern Massachusetts and Suffolk County.

The bill would also create a Massachusetts Gaming Control Authority and give the state attorney general some enforcement powers to investigate gambling crimes.

Along with a new speaker sympathetic to gambling, casino interests saw a boost in fortunes this week with a UMass-Boston study touting the quality of jobs held by casino hotel workers and a new poll showing that voters, by a 57 to 38 percent margin, believe Patrick should again propose his casinos plan.

The study, from the university's Labor Resource Center, states that casino hotel workers without a college education receive higher pay and better benefits than workers outside the industry, and unionized hotels offer better benefits in non-gambling jobs like housekeeping, dishwashing and cooking.

But some Dorchester legislators remain skeptical and point to the gambling industry, including at locations such as Twin Rivers in Rhode Island, which are facing financial difficulty in the recession.

Rep. Marie St. Fleur, who voted against Patrick's proposal last year, said she remained concerned about the negative impact on low-income families. "I haven't seen anything yet that moves me," she said.

Sen. Sonia Chang-Diaz, like her predecessor, Sen. Dianne Wilkerson, said she was also unconvinced on casinos.

"It's a revenue option, but it's a regressive revenue option," Chang-Diaz said. "Philosophically, it's very hard for me to justify solving our financial woes on the backs of the poorest residents of our state."

Rep. Linda Dorcena Forry, who joined St. Fleur and others in voting against Patrick's proposal, said she still needs to review the legislation being pushed by Walsh and Wallace.

"I'm not sure we can handle three casinos," she said.

A top casino opponent said a citizen petition drive could be launched to postpone casino legislation going through.

"If you think we're going to get instant revenues out of this, it's just not going to happen," Rep. Daniel Bosley (D-North Adams) said. "Because they're going to get enough signatures to get on the ballot."

Emerging from the Senate President's office on Monday, Patrick said his proposal was "still a good idea" but pointed to the budget crisis and the looming reorganization of the state's transportation bureaucracy. "There are some other things that we're working on right now that I think are more pressing and I think the leadership in the Legislature do as well," he said.

Material from State House News Service contributed to this report.