"His main focus is getting the people of Massachusetts back to work," said Tim Buckley, a spokesman for the state Republican Party.
The GOP has tried to use Warren's support for the Occupy protests to portray her as an extremist.
The Massachusetts Republican Party has released a video dubbing Warren the "matriarch of mayhem" — interspersing her comments with images of protesters being arrested and decrying capitalism.
Crossroads GPS, a high-powered national Republican advocacy group, has aired TV ads in Massachusetts with similar images, blasting Warren for siding "with extreme left protests."
But Warren pulled ahead of Brown in the latest poll this month. And seeing the effectiveness of her anti-Wall Street message, Crossroads reversed course.
In a TV ad that began airing this month, the group used Warren's time as head of the bailout oversight panel to try to link her to Wall Street.
"Congress had Warren oversee how your tax dollars were spent, bailing out the same banks that helped cause the financial meltdown," the ad said.
Warren, who had no say in how bailout funds were allocated, drew bipartisan praise for aggressive questioning of financial executives and Obama administration officials about how they were using the money. She called the new ad ridiculous.
The skirmish showed both sides are trying to nationalize the race, Duffy said.
"It's a huge race for Wall Street," she said. The industry worries that if Warren wins, "she's in a position to make their lives extremely difficult."