BOSTON -- Massachusetts voters will not have to wait until after next Tuesday's primary for the partisan bashing to begin.

NewsCenter 5's Janet Wu reported that Kerry Healey kicked it off on Thursday morning, targeting Chris Gabrieli.

The Democrat quickly countered.

The ad stems from Gabrieli's proposal to invest $1 billion in state money into stem cell research. The ad said Gabrieli owns stock in companies that would profit from stem cell research.

"Kerry Healey is doing her best impersonation of Karl Rove because she's worried I might win this primary," Gabrieli said.

But is Healey's charge accurate? Gabrieli said none of the biotech companies he's invested in have ever done stem cell research. But his campaign concedes they might be involved in this kind of research in the future.

"I'll be real clear about it. If it takes selling my stock in any biotech company and my stock in every company to remove any doubt about it, I will happily do that as governor," Gabrieli said.

Gabrieli said for anyone to accuse him of getting into politics to make money is ludicrous. So what's the real motivation?

"Gabrieli does run well among independents -- the best of the three. So she may be concerned about that," said Dan Payne, Democratic political analyst. "If she's worried about him, it's his money. That is the problem. He'll be able to put in a ton of money and he'll be able to do it immediately."

Healey said she's merely responding to the wholesale attacks from labor unions and all the Democrats who have been pounding away at her all summer.

Healy was asked if she looked through her own stock portfolio to make sure there were no conflicts between what she was investing in and where the state has put its money.

"I think these are questions for Chris Gabrieli. And I hope he answers them," Healey said.

Meanwhile Deval Patrick, who is leading the Democrats in most polls, dismissed the idea that he'd be the easier Democrat to defeat in November.

"The Republicans have been making miscalculations for a long time, on all levels -- fiscal level and the shell game they drive," Patrick said.

Polls show that all three Democrats would beat Healey if the general election was held today.

If Patrick wins the nomination, his campaign intends to make it a national race, which would put Healey at a disadvantage since she would have fewer political stars to import. Bill Clinton already has committed to campaigning for Patrick in October.

Healey also suggested that new attack ads on other Democrats could debut before the primary.