But pinning down Lynch, who calls himself a "Blue Dog Democrat" in the mold of Southern and heartland moderates, is no easy task. He has managed to irritate some on the left, for instance, by supporting immunity for telecom companies that aided in the Bush administration's domestic eavesdropping program.
What he lacks in ideological purity, though, he may make up in power politics. Lynch is expected to leverage his brother William J. Lynch's post as chairman of the state Democratic Party for support from elected officials. And observers say he has a leg up in courting organized labor — if only because his would-be opponents have alienated some union leaders.
Caprio has pushed for curbs on the state's increasingly expensive pension system and has suggested that even fully vested public employees will have to share in the pain — a position that has found support in public policy circles but is anathema to labor.
"It's just not a very fair way to treat people," said George Nee, secretary-treasurer of the Rhode Island AFL-CIO.
Nee adds that the union is still smarting from Roberts' public call for AFL-CIO president Frank J. Montanaro, among others, to resign from the board of Blue Cross Blue Shield of Rhode Island in 2007 after the company settled charges of influence peddling on Smith Hill.
"I think it was very poor judgment on her part," he said. "It was insulting."
Nee didn't have much to say about Lynch, only that labor does not have a lot of interaction with an attorney general. But the mere absence of controversy could be helpful.
And Patrick J. Quinn, director of the Rhode Island Service Employees International Union State Council, went a bit further — praising Lynch for his early support of candidate Obama in a state that overwhelmingly supported US Senator Hillary Clinton in the Democratic presidential primary.
But Quinn also had kind words for Roberts. And there is a chance that labor will sit out the Democratic primary altogether: Chafee, by all accounts, has a good shot at winning union support.
Labor is not the only traditional Democratic constituency that could stay on the sidelines. With Chafee in a solid position, said Lawless, the Brown professor, liberal interest groups may not want to throw in their lot with a Democrat — even at the risk of alienating Caprio, Lynch, or Roberts.
"The costs of not endorsing [in the Democratic primary], if you think that Chafee is going to ultimately pull it off, become pretty low," Lawless said.
ELIZABETH ROBERTSBut many observers expect one powerful interest group — Washington-based EMILY'S List — to get in the race.
THE OPTIMIST IN A STATE IN NEED OF A PICK-ME-UP Roberts.
The non-profit organization, which raises money for pro-choice women candidates around the country, has backed Roberts before. And with former Arizona governor Janet Napolitano in place as President Obama's Secretary of Homeland Security and Kansas Governor Kathleen Sebelius close to securing Senate confirmation as Secretary of Health and Human Services, a Roberts campaign could provide a solid opportunity to add to a depleted corps of women governors.